Elevated troponin I is associated with a worse long-term prognosis in patients undergoing beating-heart coronary surgery

Abstract

Objectives: The impacts of elevated troponin I levels after coronary artery bypass grafting (CABG) on long-term outcomes were investigated.

Methods: A total of 996 patients who underwent elective isolated CABG for stable or unstable angina were enrolled. Patients were divided into higher and lower groups based on 80th percentile postoperative peak troponin I (ppTnI) levels. The relationship between ppTnI and long-term clinical outcomes was analysed.

Results: The median ppTnI was 1.55 (2.74) ng/ml and was significantly higher in the conventional CABG subgroup than in the beating-heart CABG subgroup: 4.04 (4.71) vs 1.24 (1.99) ng/ml, P < 0.001. The 80th percentile of ppTnI was 3.3 ng/ml in the beating-heart CABG subgroup and 8.9 ng/ml in the conventional CABG subgroup. In the conventional CABG subgroup (n = 150), 10-year overall survival showed no significant difference between the higher (≥8.9 ng/ml) and lower (<8.9 ng/ml) ppTnI groups: 71% (10%) vs 76% (5%), P = 0.316. However, the beating-heart CABG subgroup (n = 846) showed significantly worse 10-year overall survival in the higher ppTnI group (≥3.3 ng/ml) than in the lower ppTnI group (<3.3 ng/ml): 64% (6%) vs 73% (3%), P = 0.010. In the beating-heart CABG subgroup, multivariable analysis showed that ppTnI exceeding the 80th percentile was a risk factor for overall death (hazard ratio: 1.505, 95% confidence interval: 1.019-2.225, P = 0.040).

Conclusions: Higher ppTnI over the 80th percentile was associated with worse long-term survival in beating-heart CABG, but not in conventional CABG.

Keywords: Coronary artery bypass; Myocardial revascularization; Off-pump; Troponin I.