Thoughts on Angiographic Guidance and DES Use in the Cath Lab
“Make a habit of two things: to help — or at least to do no harm.”
As a registered cardiovascular invasive specialist (RCIS) who is tableside for most cases, I have been programmed to anticipate the needs of the physician with whom I am working. In the presence of an angiographically significant stenosis, my thoughts begin to churn. What guiders and wires will the physician want? Are they going to request intravascular ultrasound (IVUS) or fractional flow reserve (FFR) measurements? What size and type of stent will the physician request? Will they post dilate? If the patient has multiple lesions, will they request a surgical consult? The list goes on and on. In the midst of these typical tableside ruminations, I often wonder about the treatment standards in light of the patient on the table before me.
1) IVUS and FFR
Working in the cath lab, we quickly learn the significance of a ≥ 70% stable stenosis on angiogram. We also quickly learn the limitations of using angiography alone to assess stenosis. In my experience, a ≥ 70% stenosis is interpreted in the eyes of the performing clinician. Having worked in a diagnostic lab for a few years, I soon came to appreciate a more conservative approach to treating the questionable, angiographically significant stenosis, where a pharmacotherapy approach was more common than a revascularization in these situations. When I made the switch from a diagnostic to an interventional lab, I was shocked at how differently the ≥ 70% stenosis was interpreted and likely intervened upon. Baffled as to whether a conservative or aggressive approach was more appropriate, I looked to the American College of Cardiology (ACC) and American Heart Association (AHA) guidelines for an answer.
According to ACC/AHA guidelines, appropriate revascularization should improve survival and/or relieve symptoms.(1) The guidelines deem that significant angiographic findings are ≥ 70% non left main (LM) coronary artery disease (CAD) or ≥ 50% LM CAD. So, which approach is safest for the treatment of a moderate, stable stenosis? Is it conservative treatment using a medical therapy approach or the aggressive revascularization approach?
When dealing with stable moderate stenosis, three criteria must be met for revascularization therapy: symptoms, positive physiological studies (stress testing), and angiographic significance. If one of the three criteria were not met, depending on which one, we can use IVUS and/or FFR to better understand the vessel in question. The concepts and indications of use for IVUS and FFR may be obvious to clinicians and most cath lab professionals, but it has been my experience that these tools may be overlooked.
One article I have found helpful in my search to understand IVUS is “Contemporary clinical applications of coronary intravascular ultrasound” from the Journal of the American College of Cardiology.(1) It does an excellent job explaining the value of IVUS. Angiography alone may not be sufficient when interpreting a LM or bifurcating stenosis, as well as other questionable stenoses. Using IVUS in these situations, as well as using IVUS for pre-intervention strategy and post-stent analysis, can reduce mortality and optimize patient outcomes.(2) Most of us know the other benefits of IVUS, but as a reminder, benefits include the following: appropriate vessel sizing, stenosis analysis, assisting with stent placement, and assuring proper stent apposition.Because of these benefits, should clinicians consider using IVUS after every stent implantation? This decision, ultimately, is left up to the individual physician.
FFR is also a useful diagnostic tool to determine the physiological significance of a moderate stenosis. The Fractional Flow Reserve versus Angiography for Multivessel Evaluation (FAME) study analyzed patients who had at least ≥ 50% lesions in two of the three major epicardial vessels. FAME patients were separated into two groups: those who received angiography-guided percutaneuous coronary intervention (PCI) and those who received FFR-guided PCI. FAME states, “without prolonging the procedure, the FFR-guided strategy reduced the number of stents used, decreased the amount of contrast used, and resulted in a similar, if not improved, functional status with no decrease in health-related quality of life.”(3)
What does this mean for patients? Will the government, hospitals, and/or insurance companies someday mandate that every patient receive IVUS and FFR, if clinically warranted, alongside angiography? Certainly these tools are not needed in every patient, but in the unique situations of questionable stenoses, surely treatment standards will be coming in the near future.
In fact, action is already underway. As per the Recovery Audit Program launched by way of the Center for Medicare & Medicaid Services (CMS), health care providers may be seeing new standards of care to assure proper care and appropriate reimbursements. This program is conducting retroactive audits and it will be appropriating funds for fee-for-service providers in multiple states.(4) These contractors, via the Tax Relief and Health Care Act of 2006, consist of therapists, nurses, coders, and a physician CMD.(5) Between 2005-2008, results showed that nearly 1 billion dollars in overpayments were returned to the Medicare Trust Fund and almost 40 million dollars in underpayments were returned to health care providers.(4,5) This act will certainly affect treatment standards and guidelines in the cardiac cath lab.
2) Looking at DES versus BMS and antiplatelet therapy cost
When it comes to stenting, without a doubt, drug-eluting stents (DES) have revolutionized angioplasty and the way patients have been treated for significant CAD. Since the arrival of the first FDA-approved DES in 2003(6), DES have trumped the “old school” bare-metal stent (BMS) in elective stent implantation. Multiple studies have shown the benefits of DES stent implantation(7), but should implanting physicians consider the socioeconomic factors regarding pharmacotherapy and post stent care? We have seen that some physicians are very consistent in considering socioeconomic status. On the other hand, some clinicians do not consider the patient’s socioeconomic status when administering treatment.
Unless you have been completely secluded from society for the past 10 years, you have surely heard of the trials and tribulations undergone by the United States economy. With fluctuating unemployment rates, the rate of uninsured individuals increased by over 1 million people from 2007-2008.(8) It comes as no surprise that hospital systems have felt the burden of treating a more uninsured population. Most importantly, uninsured individuals typically choose not to budget for their health care and often struggle to pay for prescription drugs. Is patient socioeconomic status impacting stent selection in your lab? What do the guidelines say? The following passage was taken from the ACC/AHA practice guidelines:
In patients who have undergone diagnostic cardiac catheterization and for whom PCI is planned, clopidogrel should be started and continued for at least 1 month after bare metal stent implantation, for several months after drug-eluting stent implantation (3 months for sirolimus, 6 months for paclitaxel), and for up to 12 months in patients who are not at high risk for bleeding.(1)
Without insurance coverage, a daily 75 mg dose of clopidogrel can cost $7.73. In one year, an uninsured patient not using an assistance program will pay $2,821.45 for continual use of clopidogrel.
With evidence emerging about late stent thrombosis (ST) with the use of DES, BMS selection in certain demographics is more cost-conscious and could have better outcomes for these patients.(9) Ultimately, the socioeconomic status of patients should be considered when choosing a stent.
Research provided in An Observational Study of Drug-Eluting Versus Bare-Metal Stents notes that, “rates of 18-month cardiac death/MI were not different between DES and BMS patients. However, after the discontinuation of clopidogrel (between months 7 and 18), these events occurred in 4.9% after DES versus 1.3% after BMS implantation.”(9) Although this study wasn’t conducted using a high number of participants, these finding should be considered.
Advocate for patients
As health care providers, we have an obligation to advocate for patients. If I was a patient and knew that there are resources available to better assess my illness, I would hope that someone would go the extra mile to make sure my procedure, and the treatment I received, was most appropriate.
The author can be contacted at firstname.lastname@example.org.
About the author. Zachary Kumor’s medical endeavors began 10 years ago as a combat medic in the United States Army. Since then, Zack has worked in the field of cardiology since 2004. He has worked for a small community hospital in Michigan, a large medical center in Tennessee, and is currently part of the VA Ann Arbor Health Care System. When he’s away from the cath lab, Zack enjoys spending time with his wife Kathryn and two children.
1. ACC/AHA Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction—Executive Summary. Available online at http://circ.ahajournals.org/content/110/5/588.full. Accessed June 4, 2012.
2. McDaniel MC, Eshtehardi P, Sawaya FJ, Douglas JS Jr, Samady H. Contemporary clinical applications of coronary intravascular ultrasound. JACC Cardiovasc Interv 2011 Nov;4(11):1155-1167. Review.
3. Pijls NH, Fearon WF, Tonino PA, Siebert U, Ikeno F, Bornschein B, van't Veer M, Klauss V, Manoharan G, Engstrøm T, Oldroyd KG, Ver Lee PN, MacCarthy PA, De Bruyne B; FAME Study Investigators. Fractional flow reserve versus angiography for guiding percutaneous coronary intervention in patients with multivessel coronary artery disease: 2-year follow-up of the FAME (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation) study. J Am Coll Cardiol 2010 Jul 13;56(3):177-184. Epub 2010 May 28.
4. Statement of Work for the Recovery Audit Program. Available online at: https://www.cms.gov/Recovery-Audit- Program/Downloads/090111RACFinSOW.pdf. Accessed June 4, 2012.
5. CMS Announces New Recovery Audit Contractors to Help Identify Improper Medicare Payments. Available online at: https://www.cms.gov/apps/media/press/factsheet.asp?Counter=3292&intNumPe.... Accessed June 4, 2012.
6. Moses JW, Leon MB, Popma JJ, Fitzgerald PJ, Holmes DR, O'Shaughnessy C, Caputo RP, Kereiakes DJ, Williams DO, Teirstein PS, Jaeger JL, Kuntz RE; SIRIUS Investigators. Sirolimus-eluting stents versus standard stents in patients with stenosis in a native coronary artery. N Engl J Med 2003 Oct 2;349(14):1315-1323.
7. Serruys PW, Kutryk MJ, Ong AT. Coronary-artery stents. N Engl J Med 2006 Feb 2;354(5):483-495.
8. DeNavas-Walt C, Proctor BD, Smith JC. Income, poverty, and health insurance coverage in the United States: 2008. Available online at: http://www.census.gov/prod/2009pubs/p60-236.pdf. Accessed June 4, 2012.
9. Pfisterer ME. Late stent thrombosis after drug-eluting stent implantation for acute myocardial infarction: a new red flag is raised. Circulation 2008 Sep 9;118(11):1117-1119.
10. Swanson R. Change is looming on the horizon for angioplasty programs… a primer to the 2011 ACCF/AHA/SCAI Guideline for Percutaneous Coronary Intervention. Cath Lab Digest February 2012;20(2):28-30.