These are exciting times for physicians to practice medicine. We have a multitude of research that supports our current practice as well as paves the way for further insightful inquiry. An attention-grabbing trial this year was the ISCHEMIA trial.
Prior studies have attempted to understand which patient subset with stable ischemic heart disease (SIHD) would benefit from revascularization. However, it is important to remember we have progressed tremendously in medical and percutaneous coronary intervention realm, and the findings from these trials need to be explored in contemporary practice. For instance, the COURAGE trial was a landmark trial that defined guidelines in SIHD subgroup of patients. However, this trial was done in the era of bare metal stents and first generation drug eluting stents (DES) were only approved by the FDA at the tail end of this trial. More recently, the ORBITA trial attempted to address this question yet again, where patients were blinded and a sham-control trial was performed. In the revascularization arm, ischemia improved, which was seen as normalization of iFR and FFR values. However, the 16.6 second improved in exercise tolerance was not statistically significant. This trial was only able to enroll 200 patients and was too small to be powered to address exercise treadmill-based endpoints.
This brings us to the ISCHEMIA trial. This trial specifically addressed optimal medical therapy (OMT) vs OMT and early invasive strategy in SIHD patients with moderate to severe findings on stress test. The exclusion criteria included those with estimated glomerular filtration rate of < 30 mL/min, recent myocardial infarction, left ventricular ejection fraction < 35%, left main stenosis > 50%. The 5,179 participants were randomized and were 64 years old on average, 23% being women, 34% nonwhite, 16% Hispanic, 41% diabetic, and 90% with history of angina. The trial was performed in 37 countries with 320 sites and an average follow up of 3.5 years. Results did not reveal a reduction of risk of primary endpoint including cardiovascular (CV) death, non-fatal myocardial infarction (MI), resuscitated cardiac arrest, and hospitalization for unstable angina or heart failure when comparing early invasive approach to conservative management in SIHD patients with moderate to severe ischemia. A reduction in major secondary endpoint of CV death or MI at medial 3.3 years was also not evident.
Procedural MIs were increased in the invasive strategy arm but spontaneous MIs were reduced in this arm. Positive outcomes were noted in the invasive strategy with patients who had extensive disease burden with improvement in angina.
ISCHEMIA has been performed in contemporary times where we don’t just offer our patients antianginals for optimal medication therapy, but we can actually impact the trajectory of the disease. Current guidelines dictate patients who have coronary artery disease should not only be managed with medications such as beta blockers and nitrates for symptom control, but also with lipid-lowering agents to alter the plaque burden and character. In addition, we also focus on lifestyle and diet modification more aggressively than we have in the past. Comparatively, we have also progressed in the interventional cardiology sphere where the DES technology has advanced tremendously. Current second generation DES are showing low target lesion and vessel revascularization rates as well as low stent thrombosis rates.
ISCHEMIA trial was able to bring the issue of individualized medical care and shared-decision making to the forefront. One management plan does not fit all. Individuals have different comorbidities, angina threshold, and varying degrees of ischemia on a stress test. We currently practice at a time when we can offer advanced conservative management as well as invasive strategy. Which management plan is better for the patient depends on their ischemia burden, anginal symptoms, and comorbidities as well as willingness to adhere to medications and management plan. We can truly try to progress to individualized medical care in conversation with the patient. And, in fact, offer the best medical care that we have ever been able to.
Dr. Supreeya Swarup is currently practicing Interventional Cardiology in Memphis, TN. Her interests include cardiovascular health and disease prevention as well as healthy diet and lifestyle. She has a passion for writing and the views expressed herein are her own. She has no disclosures or conflicts of interest.
Illustration by April Brust