[Perioperative myocardial infarction in coronary bypass surgery: characterization of risk factors, clinical pictures and prognosis].

Unlabelled: Perioperative myocardial infarction ( POMI ) in cardiac surgery is an issue that deserves to be revisited.

Objective: To evaluate the risk factors, clinical characteristics and prognosis of POMI in high-risk patients ( pts ) undergoing coronary bypass surgery ( CABG ).

Material And Methods: Retrospective study of 694 pts undergoing isolated CABG - 252 pts with conventional CABG and 442 pts with off-pump CABG - and operated on by 4 surgeons largely experienced in both CABG modalities. POMI diagnosis: biochemical criteria - 1 ) late ( at or after 24 hrs of postoperative period ) troponin ( > 7 ng/mL ) and/or CKMBm ( > 40 ng/mL ) peak values, with inverted V-shaped curves; 2 ) prolonged troponin release ( ⋝ 48 hrs ), with a plateau-like curve ( without a well defined peak ) and a normal/abnormal CKMBm curve. POMI was diagnosed in 116 pts ( 20.6 % of conventional CABG pts and 14.5 % of off-pump CABG pts, p < 0.05 ), that constituted Group ( Gr ) A. GrA pts were compared with GrB pts ( without POMI ).

Results: 1 ) Risk factors ( GrA vs GrB ): female gender 30 % vs 21 % (NS ) ; logistic Euroscore 5.6 % vs 5.9 % ( NS ); pre-operative clinical instability 17 % vs 23 % ( NS ); incomplete revascularization 39 % vs 38 % ( NS ); multi-territorial vascular disease 42 % vs 32 % ( p < 0.05 ); diffuse coronary artery disease 46 % vs 33 % ( p < 0.025 ); betablocker treatment 58 % vs 70 % ( p < 0.025 ); statin therapy for > 3 months 56 % vs 81 % ( p < 0.0001 ). 2 ) POMI clinical characteristics: asymptomatic/oligosymptomatic 70 %; severe 18 %; extensive 15 %. 3 ) Dysrhythmic profile ( GrA vs GrB ): sinus tachycardia > 115 bpm 9.6 % vs 2.9 % ( p < 0.01 ); atrial pacing for > 4 hrs 5.2 % vs 17.6 % ( p < 0.01 ); very early ( up to 2 hrs of postoperative period ) atrial tachyarrhythmia 4.3 % vs 0.9 % ( p < 0.025 ). 4 ) Hospital mortality ( GrA vs GrB ); global 9.6 % vs 2.1 % ( p < 0.001 ); cardiovascular 6.1 % vs 0.7 % ( p < 0.001 ).

Conclusions: 1 ) POMI is more frequent in conventional CABG. 2 ) Although frequently asymptomatic or oligosymptomatic, POMI shows adrenergic hyperactivity that significantly influences the postoperative dysrhythmic profile. 3 ) POMI is a marker of potentially ominous prognosis. 4 ) Instability of multiple coronary lesions seems to be the main non-technical POMI risk factor, and an intensive pre-operative treatment with statins may eventually exert an important role in POMI prevention.