By Jeffrey Zimmet, MD, PhD
Associate Professor of Medicine, University of California, San Francisco; Director, Cardiac Catheterization Laboratory, San Francisco VA Medical Center
SYNOPSIS: Researchers randomly assigned patients with an ejection fraction ≤ 35% and severe coronary disease to percutaneous coronary intervention or optimal medical therapy alone. After 3.4 years median follow-up, researchers noted no significant differences between groups in terms of all-cause death or heart failure hospitalization.
SOURCE: Perera D, Clayton T, O’Kane PD, et al. Percutaneous revascularization for ischemic left ventricular dysfunction. N Engl J Med 2022; Aug 27. doi: 10.1056/NEJMoa2206606. [Online ahead of print].
Among patients diagnosed with heart failure with reduced ejection fraction, coronary artery disease is thought to be the most common etiology. The concept that coronary revascularization by bypass surgery could affect outcomes favorably in ischemic cardiomyopathy was the subject of the Surgical Treatment for Ischemic Heart Failure (STICH) trial. In that investigation, all-cause mortality rates were not significantly lower in the coronary artery bypass grafting (CABG) group vs. medical therapy groups at five years, in part because of the early penalty seen with surgery itself.1 However, divergence of the survival curves was noted at the initial review. By 10 years, the CABG group demonstrated a survival advantage.2
The REVIVED trial was designed to test the hypothesis that revascularization by percutaneous coronary intervention (PCI) could alter hard outcomes in patients with ischemic cardiomyopathy — potentially without the early hazard seen with surgery. Researchers enrolled patients with an ejection fraction of ≤ 35% and severe coronary disease from 40 centers in the United Kingdom. Patients with recent acute coronary syndrome (ACS) were excluded, as were those with recent acute decompensated heart failure. Between August 2013 and March 2020, a total of 700 patients were randomly assigned to receive either PCI or medical therapy alone. The average age of enrolled patients was 70 years, the vast majority were white, and more than 87% were men. Overall, patients did not present with limiting angina; two-thirds showed no angina at all, while most of the remainder exhibited minimal or non-limiting angina. More than 70% of patients were New York Heart Association (NYHA) class I or II.
Among patients treated by PCI, the median number of treated vessels and lesions was two. Left main disease was present in 14%, and proximal left anterior descending disease in a little more than 50%. Completeness of revascularization, as measured by the pre- and post-PCI British Cardiovascular Intervention Society jeopardy score (BCIS-JS), was 71%. At a median follow-up of 41 months, the primary outcome of death or heart failure hospitalization had occurred in 37.2% of the PCI group and 38% of the medical therapy group (hazard ratio [HR], 0.99; 95% confidence interval [CI], 0.78-1.27; P = 0.96). The measured ejection fraction was similar between groups at six and 12 months.
Although the total incidence of acute myocardial infarction was similar between groups, approximately half these events in the PCI group were periprocedural, such that spontaneous myocardial infarction was numerically higher in the medical therapy group. This likely is related to the observation that unplanned revascularization was less frequent among PCI patients vs. those receiving optimal medical therapy alone (2.9% vs. 10.5%; HR, 0.27; 95% CI, 0.13-0.53). Quality of life scores favored PCI at six and 12 months. However, by 24 months, this difference had diminished. The authors concluded PCI, when added to a background of optimal medical therapy, did not result in significant improvement in all-cause death or hospitalization caused by congestive heart failure.
COMMENTARY
Overall, the REVIVED trial represents an impressive accomplishment for the steering committees and enrolling centers. These authors have addressed an important issue in cardiology. For patients who match the characteristics of enrolled patients, PCI did not significantly affect the outcomes of death or heart failure hospitalization. It will be interesting to delve further into the data to see which patients seemed to benefit in terms of unplanned revascularization. The early improvements in quality of life measurements also deserve further investigation.
Although we do see patients in practice who fit the general REVIVED profile, it is important we recognize those for whom these results do not apply. For example, this was not a trial of ACS patients, and these results do not apply to highly symptomatic patients. Most REVIVED subjects presented with no angina, and most were NYHA class I and II. These authors took nearly seven years to enroll across 40 sites, which speaks to the difficulty of identifying appropriate subjects. Considering the results of the STICH trial and current guidelines, some observers might speculate patients with the most severe coronary disease and high likelihood of benefit were offered CABG rather than being enrolled in the trial, thus diluting any potential treatment effect.
Another essential point is the assumption left ventricular (LV) dysfunction in these cases was secondary to coronary ischemia. It was the intent of the trial to enroll such patients; however, the data about severity of coronary stenoses and any correlation of stenosis with ischemic testing were not provided. The BCIS-JS provides an assessment of the amount of myocardial territory that may be ischemic but is agnostic to stenosis severity. For example, a left main stem lesion contributes eight points to a patient’s score, regardless of whether that lesion is 55% or 95%. One of those could be more likely than the other to cause resting myocardial dysfunction. Ultimately, the term “ischemic cardiomyopathy” may need a more sophisticated definition.
Moving forward, I expect this trial to change clinical practice for many patients. Event rates in this population are high and are not favorably affected by the routine addition of PCI to medical therapy. Clinicians will need to continue to apply their experience and judgment to symptomatic patients with coronary disease and LV dysfunction to determine where revascularization may fit in their overall treatment.
REFERENCES
1. Carson P, Wertheimer J, Miller A, et al. The STICH trial (Surgical Treatment for Ischemic Heart Failure): Mode-of-death results. JACC Heart Fail 2013;1:400-408.
2. Hassanabad AF, MacQueen KT, Ali I. Surgical Treatment for Ischemic Heart Failure (STICH) trial: A review of outcomes. J Card Surg 2019;34:1075-1082.
Researchers randomly assigned patients with an ejection fraction ≤ 35% and severe coronary disease to percutaneous coronary intervention or optimal medical therapy alone. After 3.4 years median follow-up, researchers noted no significant differences between groups in terms of all-cause death or heart failure hospitalization.
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content