Stent Restenosis: A Mediator or a Marker of Prognosis?
Journal Wrap | Although routine surveillance angiography is a valuable tool for detecting restenosis after coronary stenting, the prognostic role of restenosis is still questionable. In a recent study published in the European Heart Journal, Cassesse et al. investigated the impact of restenosis on 4-year mortality in patients undergoing routine control angiography after coronary stenting.
The authors studied 10,004 patients who underwent successful implantation of coronary stents for de novo lesions from 1998 to 2009, followed by routine control angiography after 6 to 8 months, at two centers in Germany. There were a total of 15,004 lesions in this population.
Restenosis, defined as diameter stenosis ≥50% in the in-segment area at follow-up angiography, was detected in 2,643 (26.4%) patients. The morphology was: 34% focal body, 15% focal margin, 5% multifocal, 38% diffuse, 2% proliferative, and 5% occlusive.
Overall, there were 702 deaths during the follow-up; 218 of these occurred among patients with restenosis and 484 deaths occurred among patients without restenosis, translating to an unadjusted hazard ratio of 1.19 (95% CI 1.02-1.40; p = 0.03).
After adjusting for baseline variables, Dr. Cassesse and colleagues found that restenosis was an independent predictor of 4-year mortality—the study's primary outcome—after adjusting for other baseline variables (HR = 1.23; 95% CI 1.03-1.46; p = 0.02). Other independent correlates of 4-year mortality included:
- age (HR = 2.34 for each 10-year increase; 95% CI 2.12-2.60; p < 0.001)
- diabetes mellitus (HR = 1.68; 95% CI 1.41-1.99); p < 0.001)
- current smoking habit (HR = 1.39; 95% CI 1.09-1.76); p = 0.01)
- left ventricular ejection fraction (HR = 1.39 for each 5% decrease; 95% CI 1.31-1.48); p < 0.001)
There was no difference in the long-term survival of patients with restenosis who did and did not undergo revascularization, suggesting that the ischemic burden of the restenosis is unlikely to be contributing directly to this mortality hazard.
Ultimately, restenosis was identified as an independent marker of prognosis in patients treated with stents. It is still unclear, though, if restenosis is a mediator of, or simply a marker of, poor long-term survival: it is possible that patients develop restenosis because they have more aggressive coronary artery disease, with restenosis simply acting as a surrogate for more complex coronary artery pathology.
"In this large cohort of patients, the presence of restenosis at follow-up angiography after coronary stenting was predictive of 4-year mortality," Cassesse et al. concluded. "Whether routine control angiography after coronary stenting is beneficial and influences outcomes should be evaluated by properly designed randomized trials."
- Cassesse S, Byrne RA, Schulz S, et al. Eur Heart J. 2014 October 8. [Epub ahead of print]
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