The effect of postoperative stroke and myocardial infarction on long-term survival after carotid revascularization
Jessica P Simons1, Philip P Goodney, Donald T Baril
1Division of Vascular and Endovascular Surgery, University of Massachusetts Medical School, Worcester, Mass 01655, USA.
Insights
Postoperative stroke after carotid revascularization significantly reduces short-term survival more than myocardial infarction. However, survival rates converge by five years, indicating different long-term impacts of these complications.
Area of Science:
- Vascular surgery
- Clinical outcomes research
- Cardiovascular medicine
Background:
- Carotid endarterectomy (CEA) and carotid artery stenting (CAS) have comparable overall outcomes.
- CAS carries a higher risk of stroke, while CEA has a higher risk of myocardial infarction (MI).
- The differential impact of stroke versus MI on long-term survival post-revascularization requires investigation.
Purpose of the Study:
- To compare the association of postoperative stroke versus MI with long-term survival after carotid revascularization.
- To determine if stroke or MI has a greater impact on patient survival following CEA or CAS.
Main Methods:
- Utilized the Vascular Study Group of New England database (2003-2011) for CEA and CAS procedures.
- Stratified patients based on in-hospital postoperative stroke, MI, or absence of either complication.
- Employed multivariable Cox proportional hazards models to analyze survival outcomes.
Main Results:
- Postoperative stroke (0.76%) and MI (0.97%) occurred in a small percentage of 8315 patients.
- First-year survival was significantly lower for stroke (77%) and MI (84%) groups compared to the no-complication group (96%).
- Stroke conferred a nearly twofold higher risk of mortality (HR 6.6) than MI (HR 3.6) in the first year; risks became similar by five years.
Conclusions:
- Postoperative stroke significantly decreases short-term survival more than MI following carotid revascularization.
- The survival disadvantage associated with stroke and MI converges by five years post-procedure.
- These findings highlight the distinct implications of different postoperative complications for patient outcomes and aid in interpreting composite endpoints in revascularization studies.
Introduction:
The largest randomized controlled trial that compared the efficacy of carotid endarterectomy (CEA) with carotid artery stenting (CAS) showed equivalent outcomes for the composite end point of postoperative stroke, myocardial infarction (MI), or death. However, CAS had a higher risk of postoperative stroke, and CEA had a higher risk of MI. We hypothesize that there is a differential association of postoperative stroke, compared with that of postoperative MI, with reduced long-term survival after carotid revascularization when compared with neither complication.
Methods:
The Vascular Study Group of New England database was used to identify all CEA and CAS procedures performed between 2003 and 2011. Patients were stratified according to whether they experienced an in-hospital postoperative stroke (minor or major), MI (troponin elevation, electrocardiographic changes, or clinical symptoms), or neither. Primary study end point was survival during the first year and the first 5 years postoperatively. Multivariable Cox proportional hazards models compared the magnitude of association of stroke and MI on survival.
Results:
Of 8315 patients, 81 (0.97%) experienced postoperative MI, and 63 (0.76%) experienced stroke. During the first year after operation, survival significantly differed among the three groups: neither, 96%; MI, 84%; stroke, 77% (log-rank P < .0001). After adjusting for confounders, survival after postoperative stroke (hazard ratio [HR], 6.6; 95% confidence interval [CI], 3.7-12; P < .0001) was nearly twofold less than that after postoperative MI (HR, 3.6; 95% CI, 2-6.8; P < .0001). During the first 5 years postoperatively, multivariable modeling showed postoperative stroke and postoperative MI remained independent predictors of decreased survival, but the magnitude of association was similar (HR, 2.7; 95% CI, 1.7-4.3 [P < .0001] vs HR, 2.8; 95% CI, 1.8-4.3 [P < .0001]).
Conclusions:
During the first year after operation, postoperative stroke conferred a twofold lower survival than that after postoperative MI. By 5 years after operation, these survival curves converged, and the survival disadvantage associated with stroke became similar to that of MI. These data suggest that different postoperative complications after carotid revascularization have different implications for patients, with decreased short-term survival in patients experiencing a postoperative stroke. These findings help to inform our interpretation of studies that have used a composite end point in order to evaluate the comparative effectiveness of revascularization strategies.
