The greater reduction in major adverse cardiovascular events with complete revascularization for ST-segment elevation myocardial infarction, compared with target-lesion only, persists for many years after the procedure, a study has found.
In the, researchers report the outcomes of long-term follow-up of 272 patients admitted with ST-segment elevation myocardial infarction, who were enrolled in (Complete Versus Lesion-Only Primary PCI Trial).
The trial randomized patients to complete revascularization or infarct-related artery revascularization only, with a median follow-up of 5.6 years after randomization.
, from the University of Leicester (England) and NIHR Leicester Biomedical Research Centre, and coauthors highlighted conflicting evidence on the relative benefit of complete revascularization, compared with revascularization focused on the culprit artery only.
“The aim of this study was, for the first time, to determine if there is a sustained benefit in favor of multivessel percutaneous coronary intervention [PCI] in the longer term,” they wrote.
In the group of patients who underwent complete revascularization, the composite major adverse cardiovascular event rate at 5.6 years was 43% lower than in the infarct-related artery revascularization group (24.0 vs. 37.7%; P = .0079), according to the intention-to-treat analysis.
The complete revascularization group also showed a significantly lower rate of the secondary composite endpoint of death or MI, which was 10% in the complete revascularization group and 18.5% in the target lesion group (hazard ratio, 0.47; P = .0175).
“Our data suggest that total revascularization, known to have benefits in various cohorts with coronary artery disease, should now probably be considered the standard of care in suitable patients with STEMI with multivessel disease,” they wrote.
However they did find that the rates of ischemia-driven revascularization were not significantly different between the two groups at the long-term follow-up.
The authors also did an analysis of outcomes from the end of the original 12-month study to the final follow-up point. This showed a nonsignificant trend toward a lower rate of major adverse cardiovascular events in the group who underwent complete revascularization; 17.1%, compared with 23.3% in the infarct-related artery revascularization group. The rates of the individual components of that primary endpoint also trended toward lower rates in individuals with complete revascularization.
Similarly, the rates of ischemia-driven revascularization were similar in both groups when analyzed after the 12-month mark, and the authors noted that the need for ischemia-driven revascularization was equally spread between infarct-related arteries and non–infarct-related arteries.
The authors commented that the event rate curves for the two groups remained separated even to the median follow-up point of 5.6 years, showing that the highly significant difference in major adverse cardiovascular event rates between the two groups persists.
“All of these data suggest that lower rates of events seen within 12 months do translate into longer-term benefit, predominantly through nonattenuation of benefit,” they wrote.
They speculated that the longer-term benefit of early complete revascularization could be the result of improvement in blood flow to areas around the original site of ischemia, and because it managed lesions in nontarget vessels in patients with disease in multiple arteries.
“Certainly, given that both the MRI and nuclear medicine substudies of CvLPRIT showed no difference between the groups in infarct size (at 1 week) and no difference in ischemic burden at 6 weeks, the benefit we have demonstrated does not appear to be explained simply in terms of ischemic burden being dealt with prophylactically in the complete group,” they wrote.
Commenting on the study’s limitations, the authors noted that the overall numbers of patients were small, and that the use of all-cause mortality rather than cardiovascular mortality may affect the interpretation of results.
The CvLPRIT study was funded by the British Heart Foundation, with support from the National Institute for Health Research Comprehensive Local Research Networks. No conflicts of interest were declared.
SOURCE: Gershlick A et al. .