The effect of postoperative myocardial ischemia on long-term survival after vascular surgery

Abstract

Introduction The impact of a postoperative troponin elevation on long-term survival after vascular surgery is not well-defined. We hypothesize that a postoperative troponin elevation is associated with significantly reduced long-term survival. Methods The Vascular Study Group of New England registry identified all patients who underwent carotid revascularization, open abdominal aortic aneurysm repair (AAA), endovascular AAA repair, or infrainguinal lower extremity bypass (2003–2011). The association of postoperative troponin elevation and myocardial infarction (MI) with 5-year survival was evaluated. Multivariable models identified predictors of survival and of postoperative myocardial ischemia. Results In the entire cohort (n = 16,363), the incidence of postoperative troponin elevation was 1.3% (n = 211) and for MI was 1.6% (n = 264). Incidences differed across procedures (P < .0001) with the highest incidences after open AAA: troponin elevation, 3.9% (n = 74); MI, 5.1% (n = 96). On Kaplan-Meier analysis, any postoperative myocardial ischemia predicted reduced survival over 5 years postoperatively: no ischemia, 73% (standard error [SE], 0.5%); troponin elevation, 54% (SE, 4%); MI, 33% (SE, 4%) (P < .0001). This pattern was observed for each procedure subgroup analysis (P < .0001). Troponin elevation (hazard ratio, 1.45; 95% confidence interval, 1.1–2.0; P = .02) and MI (hazard ratio, 2.9; 95% confidence interval, 2.3–3.8; P < .0001) were independent predictors of reduced survival at 5 years. Conclusions Postoperative troponin elevation and MI predict a 26% or a 55% relatively lower survival in the 5 years following a vascular surgical procedure, respectively, compared with patients who do not experience myocardial ischemia. This highlights the need to better characterize factors leading to postoperative myocardial ischemia. Postoperative troponin elevation, either alone, or in combination with an MI, may be a useful marker for identifying high-risk patients who might benefit from more aggressive optimization in hopes of reducing adverse long-term outcomes.

The Vascular Quality Initiative Cardiac Risk Index for prediction of myocardial infarction after vascular surgery

“…21,22 We recognize that late mortality after a troponin-only POMI may be from cardiovascular or noncardiovascular causes and that it is unknown if the cardiac risks are modifiable after these at-risk patients are identified. Understanding this, we combined troponin-only and clinically determined POMI as end points to obtain a more robust and clinically relevant prediction model.…”

“…20 Troponin-only POMI was included in the primary outcome, given the significant effect of troponin-only POMI on survival reported by the VSGNE and others. 21,22 Troponin-only POMI was defined as troponin elevation beyond the normal upper limit established by each center without MB elevation and without other clinical signs, symptoms, or ECG changes consistent with myocardial infarction. Clinical/ECG POMI was defined as clinical symptoms (chest pain or radiation to left arm or jaw) or ECG changes in conjunction with cardiac biomarker abnormality consistent with infarction.…”

Regional Variation in Postoperative Myocardial Infarction in Patients Undergoing Vascular Surgery in the United States

“…These differences are clinically important because previous published literature indicates that elevated serum troponin, even in the absence of ECG and/or clinical manifestations of POMI, portends a worse short- and long-term prognosis. 6,7,16–19 …”

“…In addition, troponin elevation has been demonstrated to be associated with increased short- and long-term mortality. 6,7 Within the Vascular Study Group of New England (VSGNE), a postoperative troponin elevation and POMI predict a 26% and 55% lower 5-year survival, respectively. 7 Because variation in POMI may be due to a number of factors including procedure type and patient comorbidities, notably renal insufficiency, diabetes, and preexisting coronary artery disease, risk adjustment was performed using the previously established VQI CRI (Cardiac Risk Index) all-procedures risk prediction model.…”

Preoperative Cardiac Evaluation and Management of the Patient Undergoing Major Vascular Surgery

“…Perioperative MI after vascular surgery has a mortality of 10% to 25% 25,26. Further, it is a strong predictor of elevated early (in-hospital or 30-d) and long-term mortality 25–31. The newer clinical entity of myocardial injury after noncardiac surgery (ie, significant troponin elevations after noncardiac surgery) is also associated with elevated 30-day mortality.…”