Swedish registry data point to survival benefit for younger patients undergoing CABG

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Elmir Omerovic

An analysis of data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) has shown that coronary artery bypass graft (CABG) surgery was associated with a lower rate of mortality than percutaneous coronary intervention (PCI) in patients undergoing revascularisation for left main coronary artery disease.

According to the author of the analysis, Elmir Omerovic (Sahlgrenska University Hospital, Gothenburg, Sweden), the benefit of CABG was greatest in younger patients with a longer life expectancy, while PCI was associated with a lower mortality in patients over the age of 80.

Omerovic presented findings of his analysis in late-breaking clinical trial session at the 2022 European Association of Cardio-Thoracic Surgery (EACTS) annual meeting (5–8 October, Milan Italy), having also presented the same data at the 2022 Transcatheter Cardiovascular Therapeutics meeting (TCT, 16–19 September, Boston, USA). Presenting his findings, Omerovic commented that there are few randomised trials comparing the two approaches in left main coronary artery disease, commenting that it remains unclear which—if either—is the superior approach.

The merits of the two revascularisation strategies have been a topic of contention between interventional cardiologists and cardiothoracic surgeons, with Omerovic highlighting controversy relating to the interpretation of results of the EXCEL trial—a randomised trial comparing PCI with CABG for the composite for the composite endpoint of death, myocardial infarction (MI), and stroke in patients with left main disease—as an exemplar of this thorny issue.

Aiming to bring some new insight into the debate, Omerovic and colleagues gathered data from SCAAR in order to compare PCI with CABG for the endpoint of all-cause mortality in an unselected left main coronary artery disease population. Omerovic described SCAAR as a “unique” database, encompassing all angiography procedures taking place in Sweden, input by operators in almost real time.

For their analysis, investigators analysed data from all patients undergoing coronary angiography in Sweden between 2015 and 2022 who were diagnosed with either stable angina, unstable angina or non-ST-elevation myocardial infarction (NSTEMI). Left main disease was defined as stenosis >50% on angiography. As the study was observational, the investigators used a statistical approach known as an ‘instrumental variable’ analysis, to adjust for known and unknown confounders.

In total, data were captured for 10,254 patients, 5,391 of whom underwent PCI and 4,863 CABG. Omerovic explained that there was a wide variability in the rate at which patients were likely to receive one revascularisation strategy in each hospital from which they analysed data. “We differ so much in our preference for one [approach] or the other, that there is, in other words, an act of randomness of where you happen to live and which hospital of these you belong,” he explained, displaying the data centre by centre. “If a patient is treated in a hospital with a preference for CABG, most of the time they get a treatment for CABG.”

Presenting the primary endpoint data, out of a total of 2,103 death events Omerovic revealed that the cumulative incidence of all-cause mortality was significantly greater for patients who had undergone PCI than those who had received CABG, with an adjusted hazard ratio (HR) of 1.59 (95% confidence interval 1.11–2.27, p=0.011). Looking at the differences between the two procedures across various subgroups, Omerovic added that there was very little variability when it came to sex, presence of diabetes, or patients with NSTEMI. He noted that the investigators had observed a significant interaction of a qualitative nature between those who were <80 and those who were >80, favouring PCI in the older patients, but trending towards CABG in those of lower age.

“In this observational study, CABG surgery was associated with lower mortality in patients undergoing revascularisation for left main coronary artery disease,” Omerovic said in his concluding remarks. “The benefit of CABG was highest in younger patients with a longer life expectancy.”


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