Prognosis of perioperative myocardial infarction after off-pump coronary artery bypass surgery.

Abstract

Perioperative myocardial infarction (PMI) is associated with long-term morbidity and mortality. CKMB cut-off level and importance of Q-wave MI have not been specifically studied after off-pump coronary artery bypass (OPCAB) surgery. The aim of this paper was to study the impact of PMI (CKMB >/= 20 times the upper normal limit [UNL] 100 mg/L) and CKMB rise (5-20 UNL) on survival and recurrent major adverse cardiac event (MACE) after OPCAB surgery.
One thousand consecutive prospectively followed OPCAB patients operated between September 1996 and March 2004 were analyzed. Follow-up was complete in 97% of the cohort. Average follow-up was 66 +/- 28 months.
Overall and cardiac survival at 10 years was 70 +/- 2.6% and 88 + 2.3%, respectively. Evolving MI (EMI) occurred in 1.8%, postoperative non-Q MI (NQMI) in 1.3%, and Q-wave MI (QMI) in 2.0%. Operative mortality was higher in PMI patients (P < 0.001). After adjusting for risk factors, survivors of EMI (HR: 2.0) and QMI (HR: 2.3) but not NQMI had a lower life expectancy and a higher long-term cardiac mortality (EMI: HR: 3.5; QMI: HR: 4.3) compare to non-PMI patients. EMI and QMI were associated with a decrease MACE-free survival. CKMB 5-10 UNL did not affect overall and cardiac mortality. CKMB 10-20 UNL was associated to lower cardiac survival.
PMI (CKMB > 20 UNL) was a strong predictor of operative mortality. QMI and EMI were predictors of long-term mortality and cardiac morbidity after OPCAB surgery. CKMB 10-20 UNL affected long-term cardiac survival but not overall survival.