As cardiologists have wondered about the reasons for the decline in ST-elevation myocardial infarction (STEMI) cases globally, our facility has remained busy, with the hospital registering only a mild decrease in the number of these cases. My personal belief is that patients were simply too frightened to come into a hospital and that the overall incidence of STEMI remains unaffected.
Nevertheless, the presentation of STEMI seems to have radically altered during the pandemic. Mainly, patients are presenting late with their symptoms. I relate this situation to how STEMI was performed about 15 years ago in the United States or how these cases present in developing countries: 6-8 hours after onset of symptoms with Q waves already present on the ECG and with dense, organized, fibrin-rich, red thrombus in the occluded arteries. In addition, patients are sicker and many more are pre-shock or in cardiogenic shock.
From initially experiencing a sharp decline in the number of STEMIs (attributed to the “fear factor” rather than a reduction in the incidence of STEMI from altered risk factors), we have had a gradual rise in the number of cases. The present volume of STEMI seems to be similar to the period prior to the advent of Covid-19.
In performing numerous interventions on both Covid-positive and Covid-negative patients, I have identified various tips and tricks that I have incorporated and offer as follows:
- Primary percutaneous coronary intervention (PCI) is still the preferred strategy, as thrombolysis in the Covid era is fraught with even more challenges.
- Since the processes are delayed, there is some laxity at most institutions with door-to-balloon (D2B) times. However, be mindful that short D2B times correlate clearly with the early and late outcomes, and efforts to maintain short D2B times will yield superior results.
- It may be a good idea to defer transfers for Covid-positive patients if they are clinically stable, have non-anterior acute MI, and thrombolysis can be performed early at the referral institution.
- Two early interventions we perform after EKG confirmation are obtaining a rapid Covid test and placing a face mask on the patient.
- Remember that the Covid test may be a false negative in up to 30% of cases. Yet a genuinely “rapid” result is an invaluable assistance in managing these patients. A Covid-positive patient with a small inferior or lateral wall acute MI can still be considered for thrombolysis, particularly if the presentation is not delayed. A Covid-positive patient should be preferably treated in a negative pressure catheterization laboratory. Beyond these advantages, the Covid status also helps us to comprehend some pathophysiological distinctions and better perform the procedure.
- Absolute and compulsive personal protection equipment (PPE) is essential for the entire staff. In addition, this must also hold true for the additional critical personnel that may jump in to assist with anesthesia issues, intubation, ventilator management, and to assist in resuscitation for cardiac arrest patients.
- It is better to have a strategy of solo primary PCI, as it is highly unlikely that your surgeons will emergently take a Covid-positive or equivocal patient for emergency surgery.
- Keep the procedure simple — PCI for only the culprit lesion for both patients in cardiogenic shock and those without.
- I have followed my “Chernobyl strategy” for primary PCI: get in and out quickly to avoid unnecessary Covid exposure to staff and to myself.
- Nothing fancy: Use primary PCI for its life salvage value and desist from non-culprit PCI, chasing small branches, imaging, and atherectomy devices.
- Covid-positive STEMI lesions can have profound vasospasm. Two cases with subtotal occlusion completely resolved with intracoronary nitroglycerine.
- My own preferred anticoagulant is bivalirudin, but whether using heparin or bivalirudin, compulsively monitor the activated clotting time (ACT) levels — there may be considerable variation in response to anticoagulants.
- Utilize a selective thrombus management strategy (low-grade thrombus = direct stent; intermediate = aspiration; high grade in large vessels = consider AngioJet thrombectomy [Boston Scientific])
- Use liberal doses of intracoronary vasodilators for augmenting distal microvascular flow. My preferred agent is nitroprusside (mean dose 400 mcg); we use intravenous phenylephrine for nitroprusside-induced hypotension.
- Avoid left ventriculography and right heart catheterization.
- Intra-aortic balloon pump (IABP) and Impella (Abiomed) will of course benefit the indicated patient. We have not needed either during the Covid pandemic.
Disclosure: Dr. Mehta reports no conflicts of interest regarding the content herein.
He can be contacted at firstname.lastname@example.org.