Once Again, No Survival Benefit With PCI, Surgery in Stable CAD

Patrice Wendling

June 30, 2020

Coronary revascularization does not confer a survival advantage over initial medical therapy in patients with stable ischemic heart disease (SIHD) but reduces unstable angina, according to a new study-level meta-analysis.

Routine upfront revascularization is also associated with less spontaneous myocardial infarction (MI) but this is at the cost of increased procedural infarctions, reported lead investigator Sripal Bangalore, MD, New York University School of Medicine, New York City.

"These relationships should be taken into consideration for shared decision-making for the management of patients with stable ischemic heart disease," he said in a late-breaking trial session at PCR e-Course 2020, the virtual meeting of the Congress of European Association of Percutaneous Cardiovascular Interventions (EuroPCR).

The results, simultaneously published in Circulation, are consistent with last year's ISCHEMIA trial and other contemporary trials, such as COURAGE, FAME 2, and BARI 2D, that have failed to show a reduction in mortality with revascularization alone in SIHD. Guidelines continue, however, to recommend revascularization to improve survival in SIHD based on trials performed in the 1980s when medical therapy was limited, Bangalore observed.

The updated meta-analysis included 14 randomized controlled trials, including the aforementioned, and 14,877 patients followed for a weighted mean of 4.5 years. Most trials enrolled patients who had preserved left ventricular function and low symptom burden (Canadian Cardiovascular Society Class I/II).

In the revascularization group, 87.5% of patients underwent any revascularization. Percutaneous coronary intervention (PCI) was the first procedure in 71.3%, and bypass surgery the first choice in 16.2%. In eight trials, stents were used in at least 50% of PCI patients; drug-eluting stents were mainly used in FAME 2, ISCHEMIA, and ISCHEMIA-CKD.

In eight trials, statins were used in at least 50% of patients. Nearly 1 in 3 patients (31.9%) treated initially with medical therapy underwent revascularization during follow-up.

Results show no reduction in mortality risk with routine revascularization in the overall analysis (relative risk [RR], 0.99; 95% CI, 0.90 - 1.09) or when analyzed by whether studies did or did not use stents (P for interaction = .85).

Trial sequential analysis also showed that the cumulative z-curve crossed the futility boundary, "suggesting we have great data to show that there is lack of even a 10% reduction in death with revascularization," Bangalore said.

Results were very similar for cardiovascular death (RR, 0.92; 95% CI, 0.80 - 1.06), including when analyzed by study stent status (P for interaction = .60).

There was no significant reduction in overall MI risk with revascularization, although a borderline significant 11% decrease in MIs was found in the contemporary stent era trials (RR, 0.89; 95% CI, 0.80 - 0.998).

Revascularization was associated with a 148% increase in the risk of procedural MI (RR, 2.48; 95% CI, 1.86 - 3.31) but reduced risk of spontaneous MI (RR, 0.76; 95% CI, 0.67 - 0.85).

Unstable angina was reduced in patients undergoing revascularization (RR, 0.64; 95% CI, 0.45 - 0.92), driven by a 55% reduction in the contemporary stent era trials. Freedom from angina was also greater with routine revascularization but the difference was modest, Bangalore said. There was no difference between the two strategies in heart failure or stroke.

"This meta-analysis is well done but really doesn't change what we already know," Rasha Al-Lamee, MBBS, Imperial College, London, England, told theheart.org | Medscape Cardiology. "The most important message is that intervention in stable CAD does not change survival. We don't need to rush to intervene, we have time to plan the best strategy for each patient and to modify our plans based on their response."

The analysis addresses some of the issues with previous meta-analyses that have included trials that were not strictly stable CAD trials such as SWISSI-2, COMPARE-ACUTE, and DANAMI-3-PRIMULTI, she noted. "However a study like this is only as good as the trials that are included. We must remember that unblinded trials really cannot be used to accurately assess endpoints that are prone to bias such as unstable angina and freedom from angina."

Following the presentation, dedicated discussant Davide Capodanno, MD, PhD, University of Catania, Italy, said, "We have seen beyond any doubt that there is no difference in mortality. For cardiovascular death, it's pretty much the same. It's a little bit more mixed and nuanced, the story of myocardial infarction."

"Additional science is needed to understand the prognostic implications," he said. "Of course we know that spontaneous myocardial infarction is bad, but I'm not so sure about periprocedural MI. Is this something that is as important as spontaneous myocardial infarction?"

The meta-analysis is the largest ever performed, but there was clinical heterogeneity in the individual studies, especially in the definition of MI, Capodanno observed. Because of the use of trial-level data rather than patient-level data, the analysis also could not account for adherence to treatment or the effect of stent type or medication dosage.

The MI issue really depends on the trial definition of MI, Al-Lamee said. "We need long-term follow-up from ISCHEMIA to understand what it means for our patients. While revascularization clearly increases procedural MI rates, it also results in lower spontaneous MI rates with no impact on overall MI or death," she said. "We will only know if these MIs are important if we see what impact they have in the long term."

Although the meta-analysis combined data from several decades, it's likely that the outdated revascularization techniques in the older trials are balanced out by the outdated medical therapy in the same trials, Al-Lamee observed.

The new findings can certainly be used in patient-physician discussions, with more follow-up from ISCHEMIA to provide additional insights, she said.

"We will of course hear more about the placebo-controlled efficacy of PCI in the blinded ORBITA-2 trial. And I would really like to see some of the older studies of patient and perceptions of the effect of PCI repeated," Al-Lamee said. "Now we have more data, are we informing our patients and referrers correctly of the impact of our procedures and do they truly choose revascularization with a true awareness of what it does and does not do?"

Bangalore reported grants from the National Heart Lung and Blood Institute and Abbott Vascular; and serving on the advisory boards of Abbott Vascular, Biotronik, Meril, SMT, Pfizer, Amgen, and Reata. Al-Lamee reported speaker's honorarium from Philips Volcano and Menarini Pharmaceuticals. Capodanno has disclosed no relevant financial relationships.

Circulation. Published online June 26, 2020. Full text

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