TIMI Study Group Conducts Meta-Analysis of Trials Comparing PCI and CABG

November 15, 2021—Brigham and Women’s Hospital in Boston, Massachusetts, announced the presentation of findings from a meta-analysis conducted by the medical center’s Thrombolysis in Myocardial Infarction (TIMI) Study Group that showed that percutaneous coronary intervention (PCI) with drug-eluting stents and coronary artery bypass grafting (CABG) in the treatment of left main coronary artery disease provide approximately similar 5-year survival rates for patients. The TIMI Study Group investigators found that CABG reduced the risk of having a subsequent myocardial infarction (MI) or needing repeat revascularization and that PCI had a lower risk of stroke in the first year.

The study was presented in a Featured Science session at the American Heart Association’s 2021 Scientific Sessions held November 13-15 and published simultaneously by Professor Marc S. Sabatine, MD, et al in The Lancet.

Prof. Sabatine, who is with the Division of Cardiovascular Medicine at Brigham & Women’s Hospital, commented in the press release, “There has been persistent uncertainty among clinicians regarding the optimal revascularization strategy in patients with left main disease. This collaborative effort now provides clinicians with the data they need to assist patients in reaching the best treatment decision for them.”

According to Brigham & Women’s Hospital, this new meta-analysis aggregates data from four randomized controlled trials (SYNTAX, PRECOMBAT, NOBLE, EXCEL) comparing outcomes for at least 5 years after CABG or PCI. By using detailed individual patient data from each trial, the investigators were able to go beyond previous analyses and look not only at all-cause mortality but also cardiovascular death, spontaneous and procedural MI, stroke, and coronary revascularization.

Brigham & Women’s Hospital announcement stated that the investigators determined there probably was a greater risk of dying with PCI than with CABG, but the magnitude of this risk was, more likely than not, < 0.2% per year and < 0.1% per year for dying from cardiovascular causes.

The meta-analysis found that the possible benefit of CABG appeared likely to be confined to patients with more complex coronary anatomy. However, in terms of other outcomes, for every 1,000 patients treated with PCI rather than CABG, the analysis predicted that 35 more patients would have an MI and 76 more would need repeat revascularization over 5 years. On the other hand, the finding showed a lower rate of stroke in the first year after PCI than after CABG, reported Brigham & Women’s Hospital.

After this presentation, the Society for Cardiovascular Angiography & Interventions (SCAI), issued a press release in which Kirk M. Garratt, MD, and David A. Cox, MD, reviewed the study and discussed the implications of the findings on behalf of SCAI.

Drs. Garratt and Cox noted, “In 2019, the European Society for Cardio-Thoracic Surgery (EACTS) withdrew support for European revascularization guidelines out of concern [that] conclusions drawn from randomized trial data did not accurately represent differences in late mortality and MI rates, arguing that results were superior for CABG.” They continued, “The meta-analysis presented at the American Heart Association Scientific Sessions 2021 was intended to clarify the facts around those concerns.”

The European Society of Cardiology and EACTS guidelines were published by Franz-Josef Neumann, MD, et al in the European Heart Journal (2019;40:87-165).

Drs. Garratt and Cox highlighted that the difference in all-cause death shown in the meta-analysis was chiefly due to greater noncardiovascular deaths after PCI. Additionally, they observed, “If a mortality difference does exist, it is sufficiently small that it should not preclude consideration of PCI.”

They further stated, “The MI data analysis confirmed that the definition used impacts estimated risk: The protocol definition yielded significantly more procedural MIs with CABG, and the [World Health Organization] Universal Definition yielded no important difference in procedural MIs.” Additionally, they stated, “CABG resulted in fewer spontaneous MIs (6.2% vs 2.6%; hazard ratio, 2.35 [1.17-3.23]; P < .0001) but not lower rates of cardiovascular death.”

“These findings suggest that the European guidelines were reasonable and appropriate; new United States revascularization guidelines are anticipated in the next few months,” advised Drs. Garratt and Cox in the SCAI statement.