Octogenarians and Issues in Cath Lab Care

Richard J. Merschen, EdS, RT(R)(CV), RCIS, Ibrahim Khormi, MS, RT(R)(T)(CT)(MR), Lamis Jada, MS, RT(MR), Tamara Kobakhidze, MS, RT(R), Jennifer Robinson, MS, RT(R), Jefferson School of Health Professions and Pennsylvania Hospital, Philadelphia, Pennsylvania

Richard J. Merschen, EdS, RT(R)(CV), RCIS, Ibrahim Khormi, MS, RT(R)(T)(CT)(MR), Lamis Jada, MS, RT(MR), Tamara Kobakhidze, MS, RT(R), Jennifer Robinson, MS, RT(R), Jefferson School of Health Professions and Pennsylvania Hospital, Philadelphia, Pennsylvania

This article received a double-blind peer review from members of the Cath Lab Digest editorial board. The authors can be contacted via Richard Merschen, EdS, RT(R)(CV), RCIS, at richardmerschen@verizon.net.

Who are octogenarians?

Octogenarians represent 12% of the cath lab referral base.1 In 1982, the average life expectancy in the United States was 75.5 years old, and it has progressively increased to over 80 years of age.2,3 Octogenarians are the most rapidly growing age group and their numbers will triple by 2050. By then, they will become the most populous age group — 32.5 million persons, or 7.4% of the entire U.S. population.4

The elderly represent the fastest-growing group of patients referred for cardiac surgery and are also becoming an increasingly large segment of the patients in the cath lab. There are many issues that complicate their care, including high co-morbidity rates, frailty, and disability. Octogenarians have substantially higher rates of coronary artery disease (CAD) and cardiovascular disease than the general population. They currently represent 5% of the U.S. population, 20% of all myocardial infarction (MI) hospitalizations, and 30% of all MI-related hospital deaths. Octogenarians typically have more extensive CAD, multi-vessel disease, artery calcification, vessel tortuosity, and greater likelihood of a previous MI.5 Angina pectoris, stable and unstable, is very common in the elderly, and a high percentage of them have atypical manifestations of myocardial ischemia, including dyspnea and worsening heart failure.5,6 This article seeks to raise awareness of octogenarians, discuss their clinical challenges, and offer guidelines to improve care and outcomes.


Octogenarians pose many challenges for the cath lab team, including significantly higher rates of co-morbidities like hypertension, CAD, peripheral vascular disease, atrial fibrillation (AF), chronic kidney disease, cerebrovascular disease, chronic obstructive pulmonary disease (COPD), arthritis, dyslipidemia, diabetes and cardiomyopathy. They also have much higher rates of dementia, lower tolerances to sedation, and high risks for procedural and post procedural complications. Bleeding risks are a major concern for octogenarians, and procedural anticoagulation and long-term antiplatelet therapy need to be carefully managed. 

The value of scoring systems in assessing risk

When assessing CAD and determining treatment strategies, SYNTAX scores evaluate the number and severity of coronary lesions, the overall significance of CAD, and provide guidelines for treatment. Since octogenarians with CAD often have high SYNTAX scores, they may be percutaneous coronary intervention (PCI) or surgical candidates. Because they often have high SYNTAX scores, it is also important to evaluate surgical risks for octogenarians in order to determine treatment strategies.

Mortality and morbidity scores for CABG include the Society of Thoracic Surgeons (STS), EuroSCORE II, Parsonnet, Cleveland Clinic, and Northern New England. While each of these scores is valuable, the ACEF or Clinical SYNTAX score (CSS) (age, creatinine, ejection fraction scoring system) is an excellent scoring system that evaluates fewer co-morbidities (Table 1). The ACEF score uses: age (years)/ejection fraction (%) +1 (if serum creatinine value is >2 mg/dL) and can easily be calculated in the lab. Using this criterion, the cardiac surgery complication rates for octogenarians are generally much higher than the general population. For example, an 80-year-old patient with an ejection fraction of 40 and a creatinine of 1.5 would have an ACEF score of 2.0 and be considered high risk (80/40+ 0= 2.0). 

  • ACEF (low) ≤1.0225
  • ACEF (mid) ≤1.277 
  • ACEF (high) >1.2777

Since it only uses three major factors, ACEF is easy to calculate and is a generally reliable evaluation tool for assessing surgical risks. When ACEF (CSS) was compared to the other surgical score tools, it proved highly effective, because age, creatinine and ejection fraction are universally identified by all these tools as top-tier risk factors.7 SYNTAX and surgical risk scores provide important information about managing octogenarians, because their scores are usually high in both areas.8 In these cases, it is imperative that an interdisciplinary approach is incorporated that includes cardiothoracic surgery, interventional cardiology, anesthesia, and other potential team members. It is also helpful to be familiar with the other risk scores (Table 1), especially the STS scoring system, as it is used to assess surgical risk for transcatheter aortic valve replacement (TAVR) patients, who are increasingly seen in the cath lab setting. Many of these scoring systems have online calculators that allow staff to practice and learn how to assess surgical risks for cath lab patients.

Risk scores alone may be inadequate in assessing octogenarian risks. Frailty and disability scores also predict outcomes. These scores complement co-morbidity scores, and provide additional tools to assess risks and survival rates. Frailty is a geriatric syndrome of impaired resiliency to stressors (such as cardiac surgery) that has been delineated in the geriatric and cardiovascular literature.9 Disability is an impaired ability to carry out functional tasks. Although there is overlap between the concepts of frailty, disability, and co-morbidity, it is generally agreed that each represents distinct markers for outcomes. With the growth of minimally invasive and transcatheter cardiac interventions, including TAVR and percutaneous aneurysm repairs, it is increasingly important to evaluate patient risk factors in more depth. Use of these tools is becoming a high priority in clinical practice.9 Table 2 shows some of the risk factors associated with frailty and disability.

Pre-procedural workup

After assessing an octogenarian and determining the need for catheterization, how should they be managed? A comprehensive pre-procedural screening process should include blood work, addressing patient medications, and evaluating pulses. Access routes should be carefully selected, with an emphasis on radial artery access. A psychosocial evaluation should be performed. Anesthesia support should be strongly considered for octogenarians who require more than minimal amounts of conscious sedation. Finally, post procedural care needs to ensure that octogenarians are followed up properly, given the appropriate medical therapy and that they are carefully monitored for latent complications.

Blood work is extremely important. Octogenarians are more likely to have kidney and liver dysfunction, heart failure, atrial fibrillation, anemia, and other issues that affect laboratory values. Comprehensive assessment of blood work allows practitioners to properly plan procedures, including contrast administration, anticoagulation strategies, and arrhythmia management.

Renal function is often abnormal in octogenarians, and slight elevations in serum creatinine may be associated with advanced kidney disease. Co-morbidities such as diabetes and hypertension that accelerate age-related decrease in glomerular filtration rate (eGFR) are often present. Abnormal eGFR in octogenarians is not benign, and 26% of elderly patients have stage 3 to stage 5 chronic kidney disease.10 An 80-year-old white female, who has a creatinine of 1.4 and weighs 70kg, for instance, will have an eGFR of 33.8. eGFR assessment is important and should influence anticoagulation strategies, procedural hydration, and contrast dosage.11 The Cockcroft Gault or the Modification of Diet in Renal Disease (MDRD) formulas (Table 3), can be used for detailed assessment of kidney function in the cath lab.11

Among individuals with chronic kidney disease (CKD), the stages are defined according to kidney function. According to renal societies such as the National Kidney Foundation and government health agencies such as the National Institutes of Health, there are five stages of CKD:

  • Stage 1: Kidney damage with normal or increased glomerular filtration rate (GFR) (>90 mL/min/1.73m2);
  • Stage 2: Mild reduction in GFR (60-89 mL/min/1.73m2);
  • Stage 3: Moderate reduction in GFR (30-59 mL/min/1.73m2);
  • Stage 4: Severe reduction in GFR (15-29 mL/min/1.73m2);
  • Stage 5: Kidney failure (GFR <15 mL/min/1.73m2 or dialysis).14

In many octogenarians, mild to moderate elevations in creatinine levels do not reflect the drop in eGFR or severity of kidney disease, so these five stages are useful in assessing the severity of CKD in octogenarians.  

In some cases, serum cystatin C in an octogenarian may be helpful if there is concern about the reliability of the eGFR.15 Serum cystatin C may be more precise in assessing early onset of renal disease and renal function. Cystatin C is freely filtered across the glomerular membrane, and is not influenced by age, sex, muscle mass, exercise or diet. Therefore, in octogenarians, serum cystatin C level may be superior for evaluating renal function as compared to creatinine or eGFR.16

Decreased renal function can also affect drug clearance in patients with cardiovascular disease. Low molecular weight heparins (LMWH) are cleared in the urine, so assessing renal function is important when prescribing them in octogenarians. Therapeutic doses of LMWH can increase bleeding risks, and mild decreases in creatinine clearance can lead to accumulation of LMWHs.17 The kidneys are also important in the clearance of cath lab anticoagulation drugs such as bivalirudin and eptifibatide. Whatever anticoagulation strategies are chosen for PCI, octogenarians need to be carefully monitored for impaired renal function to avoid overmedication.

Hematology and coagulation factors should be evaluated to assess bleeding risks and limit complications. AF, anemia, and liver dysfunction are more common in octogenarians and each increase bleeding risks and complications. AF affects more than 10% of individuals >80 years old18 and these patients are frequently on blood thinners such as warfarin or dabigatran (Pradaxa). Major bleeds in octogenarians can be devastating, and transfusions after catheterization complications are associated with high short- and long-term mortality rates.19 Therefore, checking hemoglobin, platelets, PT, PTT and INR are essential when working with these patients.

Other blood work such as electrolytes and blood glucose should be assessed. Many octogenarians have heart failure and may be treated with diuretics. They also have higher rates of arrhythmia. Therefore, potassium and other electrolytes need to be reviewed. Octogenarians are more likely to be diabetic, which can cause many issues, including iatrogenic hypoglycemia, which can be devastating during cardiac catheterization.

It is crucial to know which medications octogenarians are taking. With high co-morbidity rates, octogenarians may be taking numerous medications for congestive heart failure, vascular disease, pulmonary embolus prophylaxis, hypertension, dementia, arthritis, and other diseases. Documenting and managing medications is essential, as certain medications may need to be discontinued or adapted for procedures. Patient medications will also influence management of co-morbidities that may have to be addressed around the procedure. 

Octogenarians have increased rates of carotid and peripheral vascular disease, and diffuse vascular disease is commonly seen in the cath lab.20 Therefore, thorough pulse assessments should be performed. This includes upper and lower extremity checks to evaluate disease and determine access routes. Pre-procedural tests such as ultrasounds and ankle-brachial index (ABI) should be available for review prior to catheterization. 

Procedural considerations 

There is a growing body of literature that recommends a radial artery approach to reduce major bleeding during catheterization. Major bleeding, especially after acute coronary syndromes, significantly increases morbidity and mortality in octogenarians. Several trials such as the OCTO-PLUS STEMI in the ORA-STEMI21 trials support radial access for octogenarians. Radial access significantly reduces access-related complications such as hematomas, retroperitoneal bleeds, pseudoaneurysms, and bleeding. When femoral artery access is used in octogenarians, operators should carefully manipulate catheters and wires. Over-the-wire techniques should be considered in order to limit embolic showers, as well as the use of longer sheaths to navigate vessel tortuosity and anticoagulation strategies to reduce access-related bleeding. 

The overwhelming majority of octogenarians have hypertension, and it is properly controlled in only 38% of men and 23% of women >80 years of age.22 In longstanding hypertension, arteries may become tortuous, atherosclerotic, and vulnerable to access-related bleeding. Octogenarians are at increased risks for hemorrhagic and non-hemorrhagic stroke from catheter and guide wire manipulations, and anticoagulation use.

Longstanding systolic hypertension can reduce vessel elasticity, cause low cardiac output due to decreased stroke volume and high peripheral resistance, and impact kidney function. These problems are magnified in patients with CAD, and it is important for cath lab practitioners to be aware.23 The HYVET and ACCOMPLISH trials studied the elderly and concluded that blood pressure should generally be maintained around 140-150 systolic.24 Procedural management of patients should focus on maintaining blood pressure and avoiding overmedication, as iatrogenic hypotension is life threatening.

Congestive heart failure and diminished ejection fraction are identified as major risk factors for octogenarians. Therefore, it is important that they have a left ventricular (LV) assessment. This should be performed non-invasively to minimize contrast. Echocardiography is an excellent method to assess LV function. However, an LV gram can provide value, if kidney function is normal and contrast dosing is limited. Right heart catheterization or LV end diastolic pressure (LVEDP) may be beneficial to evaluate cardiac status. Cardiac catheterization can also determine if there is an ischemic component to congestive heart failure and if so, patients can undergo revascularization to improve cardiac function.

Catheterization often requires sedation, and may require general anesthesia for complex procedures. Pre-procedural assessment is important to evaluate risk of sedation. Anesthesia should be considered to manage high-risk octogenarians who require more than minimal sedation. At least 20% of octogenarians and 33% >85 years of age have some level of dementia, including Alzheimer’s disease. They may become agitated and experience hypotension, which can affect cerebral perfusion, causing neurological deficits and cognitive impairment.25 Table 4 demonstrates major sedation issues for the elderly.

The ability of elderly people to metabolize drugs is significantly diminished in patients >70 years old. Octogenarians often have a lower cardiac output, which reduces blood flow to the liver.26 Liver and kidney function are diminished in octogenarians, further complicating sedation strategies. Body mass is reduced in octogenarians and the action of sedatives that accumulate in fatty tissue is prolonged. Because of these factors, it is important to give sedation time to circulate in the elderly to avoid overmedication.

It is important to maintain blood pressure and respiratory status in sedated octogenarians. They have decreased respiratory drive and lung capacity, which further influences the use of sedation in the cath lab.27 Expert airway management skills are essential when working with sedated octogenarians. Octogenarians do not thermoregulate as efficiently as younger adults and they can be subject to hypothermia during procedures. Shivering can result in substantially higher oxygen consumption rates, so patients should be kept warm to reduce shivering. Sedation should be given in low doses, slowly increased if necessary, and vital signs should be vigorously monitored.28   

Psychosocial status

The psychosocial status of the elderly patient can pose challenges.29 Patients may suffer depression and anxiety because of co-morbidities and cognitive impairment. Depression can complicate the patient’s prognosis by increasing physical disability, and decreasing motivation and adherence to prescribed medications. A lack of social support and isolation is also associated with increased morbidity and mortality in octogenarians after MI.5 To ensure the best chance of long-term success, it is important to ensure that patients can hear and clearly understand the procedure, and that they have social support structures in place. This includes the use of resources such as social workers and tending to the spiritual needs of the patient. Even simple issues like a fear of falling should be addressed. Making patients comfortable is extremely important, especially for those who may be fragile and arthritic.

Post procedure concerns 

Short- and long-term bleeding is a major concern for octogenarians. Scores like HAS-BLED and ATRIA help estimate bleeding risks.30 Assessment of the risk-benefit for long-term anticoagulation is a challenge in working with octogenarians. Patients at the highest hemorrhagic risk are often those who achieve the greatest benefit from anticoagulants. Few guidelines exist on the use of anticoagulants in octogenarians, but since these patients represent a considerable subset in trials on deep vein thrombosis prophylaxis and AF, these study results may be useful for octogenarians.31

Trials such as REPLACE 232 evaluated anticoagulation strategies during cardiac catheterization. While octogenarians are poorly studied in clinical trials on anticoagulation, the general guidelines of REPLACE 2, which recommend bivalirudin to reduce bleeding, are probably best suited for octogenarians. Other trials33 that studied octogenarians on a limited basis also found bivalirudin to be superior to heparin for bleeding risk and short-term mortality. Before anticoagulating octogenarians, calculate eGFRs to determine if renal dosing is required instead of full dosing for these medications.

The best long-term antiplatelet strategies for the elderly require careful consideration. In patients with acute coronary syndromes with or without ST-segment elevation, treatment with ticagrelor as compared with clopidogrel significantly reduced the rate of death from vascular causes, myocardial infarction, or stroke, without an increase in the rate of overall major bleeding, but with an increase in the rate of non-procedure-related bleeding.34 Prasugrel is contraindicated in patients >75 years old. 

Should PCI be an available treatment strategy for octogenarians? 

Literature with a focus on octogenarians is lacking and these patients are often excluded from clinical trials. Many studies either exclude octogenarians because of age or increased co-morbidity rates. Moreover, additional enrollment criteria are often based on age-related conditions, including renal dysfunction, life expectancy, and cancer.35

There is debate about the best treatment strategies for octogenarians with CAD. According to geriatric philosophy, PCI should be performed on symptomatic elderly patients, and while procedural and post procedural complication rates may increase, octogenarians who are treated do well in the short term and have significantly higher survival rates for acute coronary syndromes. In clinical trials35, antianginal drug therapy relieved symptoms in only 57% of patients. Patients who were revascularized for refractory symptoms reported less angina, with less medical therapy, during long-term follow-up and had better long-term survival. However, a long-term follow-up analysis of the Trial of Invasive versus Medical therapy in Elderly (TIME) trial concluded that aggressive medical therapy over PCI in symptomatic patients needs to be reconsidered.36

Data from clinical trials such as CRUSADE concluded that usage of acute antiplatelet and antithrombin therapy within the first 24 hours of presentation decreased with age. Octogenarians were less likely to undergo early catheterization or revascularization. While discharge medication was similar in all age groups, clopidogrel and lipid-lowering therapy were prescribed less in elderly patients. In-hospital mortality and complication rates increase with age, but those patients receiving more recommended therapies had lower mortality than those who did not. As newer pharmacological agents and early in-hospital care improves, improved outcomes for elderly patients are more likely if they undergo earlier coronary intervention.37

Drug-eluting stents should be the preferred method for treatment in most octogenarians. 

The XIMA trial found that octogenarians requiring stenting for coronary disease had significantly lower rates of target vessel revascularization and MI when treated with drug-eluting stents, with no difference in mortality between drug-eluting and bare-metal stent groups at one year. There were also similar rates of major hemorrhage in each group, despite differing dual antiplatelet therapy regimens.38 

Final reminders and suggestions

Ultimately, the management of most cardiac diseases in the older patient should be similar to that of the younger patient, with proper management of medication therapies. Age should not be an absolute contraindication to invasive procedures or surgical procedures, since when properly selected, these procedures may provide greater benefits for octogenarians.

Post procedure, octogenarians should be considered a high-risk subset. They need to be carefully monitored to minimize bleeding risks and other complications such as stroke, MI, kidney failure, and uncontrolled hypertension. When possible, octogenarians should have their procedures done early in the day, to eliminate potential issues from dementia, return them to their normal medication regimens, and get them back to their daily routines as soon as possible. It is also important to make sure that these patients are able to keep follow-up appointments and that they are self-aware enough to monitor themselves — or a care provider is able to monitor them — for late complications such as kidney failure or bleeding.

Octogenarians represent the most rapidly growing segment of the population. They are an increasingly large segment of the cath lab population, and simultaneous to interventional cardiology’s expansion in scope to include TAVR, mitral clipping procedures, and percutaneous aneurysm repairs, their numbers will continue to grow. The cardiology field is moving towards performing PCI, other interventional procedures, and coronary artery bypass graft surgery on octogenarians, especially when co-morbidity, frailty and disability scores are acceptable. Clinical trials, which are severely limited on the elderly, support earlier PCI in octogenarians. Many advances in cardiology are reducing short- and long-term complication rates, including the use of radial artery access, better anticoagulation and antiplatelet therapy options, an increased understanding of co-morbidities, more advanced percutaneous intervention options, and advances in technology such as drug-eluting stents. We need more clinical trials tailored towards octogenarians, an increasingly large segment of the population, with the goal of improving their quality of life and offering the best treatment options available, without unnecessary delays. Octogenarians generally have multiple major co-morbidities, frailty, and disabilities that complicate their care. It is imperative to be proactive when working with octogenarian patients. A well-planned care strategy should include:

  1. A comprehensive overview and management plan for co-morbidities, frailty,  and disability levels;
  2. Complete laboratory values to proactively manage the patient;
  3. Full pulse assessments in order to determine the best access routes, with emphasis on the radial approach;
  4. Carefully managing the patient’s medications and adjusting them for the procedure;
  5. A comprehensive evaluation of mental status and psychosocial needs;
  6. A carefully planned sedation strategy;
  7. Anticoagulation and antiplatelet strategies that factor in co-morbidities and age;
  8. Post procedural care that minimizes bleeding and kidney failure;
  9. Avoiding unnecessary delays in providing care for octogenarians, especially those with acute coronary syndromes;
  10. The use of drug-eluting stents for PCI.



  1. National Cardiovascular Data Registry. CathPCI Registry. 2014. Available online at: https://www.ncdr.com/webncdr/cathpci/. Accessed June 1, 2014.
  2. Huber CH, Goeber V, Berdat T, Carrel P, Eckstein F. Benefits of cardiac surgery in octogenarians — a postoperative quality of life assessment. Eur J Cardiothorac Surg. 2007 Jun; 31(6): 1099-1105. 
  3. Foot DK, Lewis, RP, Pearson TA, Beller GA. Demographics and Cardiology, 1950-2050. J Am Coll Cardiol. 2000 Mar 15; 35(4): 1067-1081. 
  4. Heisler EJ, Shrestha LB. The changing demographic profile of the United States. March 31, 2011. Congressional Research Service. Available online at http://fas.org/sgp/crs/misc/RL32701.pdf. Accessed August 4, 2014.
  5. Williams MA, Fleg JL, Ades PA, Chaitman BR, Miller NH, Mohiuddin SM, Ockene IS, Taylor CB, Wenger NK; American Heart Association Council on Clinical Cardiology Subcommittee on Exercise, Cardiac Rehabilitation, and Prevention.  Secondary prevention of coronary heart disease in the elderly (with emphasis on patients > or =75 years of age): an American Heart Association scientific statement from the Council on Clinical Cardiology Subcommittee on Exercise, Cardiac Rehabilitation, and Prevention. Circulation. 2002 Apr 9; 105(14): 1735-1743.
  6. Holliman K. Managing the elderly with cardiovascular disease. ACP Internist. 2011 October. Available online at http://www.acpinternist.org/archives/2011/10/CVD.htm. Accessed August 4, 2014. 
  7. Ranucci M, Castelvecchio S, Menicanti L, Frigiola A, Pelissero G. Risk of assessing mortality risk in elective cardiac operations: age, creatinine, ejection fraction, and the law of parsimony. Circulation. 2009 Jun 23; 119(24): 3053-3061. doi: 10.1161/CIRCULATIONAHA.108.842393. 
  8. Scherff F, Vassalli G, Sürder D, Mantovani A, Corbacelli C, Pasotti E, Klersy C, Auricchio A, Moccetti T, Pedrazzini GB. The SYNTAX score predicts early mortality risk in the elderly with acute coronary syndrome having primary PCI. J Invasive Cardiol. 2011; 23(12): 505-510.
  9. Afilalo J, Mottillo S, Eisenberg MJ, Alexander KP, Noiseux N, Perrault LP, et al. Addition of frailty and disability to cardiac surgery risk scores identifies elderly patients at high risk of mortality or major morbidity. Circ Cardiovasc Qual Outcomes. 2012 Mar 1; 5(2): 222-228.
  10. Coresh J, Astor B. Decreased kidney function in the elderly: clinical and preclinical, neither benign. Ann Intern Med. 2006; 145(4): 299-301. 
  11. Stevens LA, Li S, Kurella Tamura M, Chen SC, Vassalotti JA, Norris KC, Whaley-Connell AT, Bakris GL, McCullough PA. Comparison of the CKD Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) study equations: risk factors for and complications of CKD and mortality in the Kidney Early Evaluation Program (KEEP). Am J Kidney Dis. 2011 Mar; 57(3 Suppl 2): S9-S16. doi: 10.1053/j.ajkd.2010.11.007.
  12. National Kidney Disease Education Program. Health Professionals: GFR MDRD calculator for adults (conventional units). Available online at: http://nkdep.nih.gov/lab-evaluation/gfr-calculators/adults-conventional-unit.asp. Accessed August 4, 2014.
  13. Creatinine clearance (Cockcroft-Gault Equation). Available online at: http://www.mdcalc.com/creatinine-clearance-cockcroft-gault-equation. Accessed August 4, 2014.
  14. National Kidney Foundation. KDOQI clinical practice guidelines for chronic kidney disease: Evaluation, classification, and stratification. Available online at: http://www.kidney.org/professionals/kdoqi/guidelines_ckd/p4_class_g1.htm. Accessed August 4, 2014. 
  15. Fliser D. Assessment of renal function in elderly patients. Curr Opin Nephrol Hypertens. 2008; 17(6): 604-608. 
  16. Fu Z, Xue H, Guo J, Chen L, Dong W, Gai L, Chen Y. Long-term prognostic impact of cystatin C on acute coronary syndrome octogenarians with diabetes mellitus. Cardiovasc Diabetol. 2013 Nov 1; 12(1): 157. doi: 10.1186/1475-2840-12-157. 
  17. Nagge J, Crowther M, Hirsh J. Is impaired renal function a contraindication to the use of low-molecular-weight heparin? Arch Intern Med. 2002 Dec 9-23; 162(22): 2605-2609.
  18. Schwartz JB, Zipes DP. Cardiovascular disease in the elderly. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa:Saunders; 2011:chap 80.
  19. Mahaffey KW. Acute coronary syndromes: what have we learned about what we still need to know? Tex Heart Inst J. 2006; 33(2): 187-189. 
  20. Na CR, Wang S, Kirsner RS, Federman DG. The elderly and peripheral arterial disease. Clinical Geriatrics. 2011;19(7):41-46. 
  21. Louvard Y, Lefevre T, Allain A, Morice MC. Coronary angiography through the radial or the femoral approach: The CARAFE study. Catheter Cardiovasc Interv. 2001; 52: 181-187.
  22. Lionakis N, Mendrinos D, Sanidas E, Favatas G, Georgopoulou M. Hypertension in the elderly. World J Cardiol. 2012; 4(5): 135-147.
  23. Staessen JA, Fagard R, Thijs L, Celis H, Arabidze GG, Birkenhäger WH, et al. Randomised double-blind comparison of placebo and active treatment for older patients with isolated systolic hypertension. Lancet. 1997 Sep 13; 350(9080): 757-764.
  24. Garrett AD. New AHA guidelines help manage hypertension in the elderly. Drug Topics. Voice of the Pharmacist. April 15, 2012. Available online at http://drugtopics.modernmedicine.com/drug-topics/news/modernmedicine/modern-medicine-feature-articles/new-aha-guidelines-help-manage-hype?page=full. Accessed August 4, 2014.
  25. Salma S. Anesthesia for the elderly patient. Journal of Pakistan Medical Association. April 2007. Available online at http://jpma.org.pk/full_article_text.php?article_id=1074. Accessed August 4, 2014.
  26. Sieber FE, Barnett SR. Preventing postoperative complications in the elderly. Anesthesiol Clin. 2011 Mar; 29(1): 83-97. doi: 10.1016/j.anclin.2010.11.011.
  27. Conway A, Page K, Rolley J, Fulbrook P. Risk factors for impaired respiratory function during nurse-administered procedural sedation and analgesia in the cardiac catheterisation laboratory: a matched case-control study. Eur J Cardiovasc Nurs. 2013 Aug; 12(4): 393-399. doi: 10.1177/1474515112470351.
  28. Yohannes AM, Baldwin RC. Medical comorbidities in late-life depression. Psychiatric Times. 2008 Dec 1. Available online at http://www.psychiatrictimes.com/articles/medical-comorbidities-late-life-depression. Accessed August 4, 2014.
  29. Roldán V, Marín F, Fernández H, Manzano-Fernandez S, Gallego P, Valdés M, Vicente V, Lip GY. Predictive value of the HAS-BLED and ATRIA bleeding scores for the risk of serious bleeding in a “real-world” population with atrial fibrillation receiving anticoagulant therapy. Chest. 2013; 143(1): 179-184.  
  30. Robert-Ebadi H, Gal GL & Righini M. Use of anticoagulants in elderly patients: practical recommendations. Clinical Interventions in Aging. 2009; 4: 165-177.
  31. Lemesle G, De Labriolle A, Bonello L, Syed A, Collins S, Maluenda G, Waksman R. Impact of bivalirudin on in hospital bleeding and six month outcomes in octogenarians undergoing percutaneous coronary intervention. Catheter Cardiovasc Interv. 2009 Sep 1; 74(3): 428-435. doi: 10.1002/ccd.22007.
  32. Gruberg L. REPLACE-2: Randomized Evaluation of PCI Linking Angiomax to Reduced Clinical Events. Medscape: News & Perspective. Nov 20, 2002. Available online at http://www.medscape.com/viewarticle/444903. Accessed August 4, 2014.
  33. Wallentin L, Becker RC, Budaj A, Cannon CP, Emanuelsson H, Held C, Horrow J, Husted S, James S, Katus H, Mahaffey KW, Scirica BM, Skene A, Steg PG, Storey RF, Harrington RA; PLATO Investigators, Freij A, Thorsén M. Ticagrelor versus clopidogrel in patients with acute coronary syndromes. N Engl J Med. 2009 Sep 10;361(11):1045-57. doi: 10.1056/NEJMoa0904327.
  34. Lazzarini V, Mentz RJ, Fiuzat M, Metra M, O’Connor CM. Heart failure in elderly patients: distinctive features and unresolved issues. Eur J Heart Fail. 2013; 15(7): 717-723. 
  35. Shanmugasundaram S. Percutaneous coronary intervention in elderly patients: is it beneficial? Tex Heart Inst J. 2011; 38(4): 398-403.
  36. Bonetti PO, Kaiser C, Zellweger MJ, Grize L, Erne P, Schoenenberger RA, Pfisterer ME. Long-term benefits and limitations of combined antianginal drug therapy in elderly patients with symptomatic chronic coronary artery disease. J Cardiovasc Pharmacol Ther. 2005; 10(1): 29-37.
  37. Alexander KP, Roe MT, Chen AY, Lytle BL, Pollack CV Jr, Foody JM, Boden WE, Smith SC Jr, Gibler WB, Ohman EM, Peterson ED; CRUSADE Investigators. Evolution in cardiovascular care for elderly patients with non-ST-segment elevation acute coronary syndromes: results from the CRUSADE National Quality Improvement Initiative. J Am Coll Cardiol. 2005; 46(8): 1479-1487.
  38. American College of Cardiology. XIMA: are DES superior to BMS in octogenarian patients? October 26, 2012. Cardiology Magazine. Available online at: http://www.cardiosource.org/News-Media/Publications/Cardiology-Magazine/2012/10/XIMA.aspx?w_nav=Search&WT.oss=octogenarians&WT.oss_r=31. Accessed August 4, 2014.