Does on-pump/beating-heart coronary artery bypass grafting offer better outcome in end-stage coronary artery disease patients?

Abstract

The purpose of our study was to evaluate in a cohort of end-stage coronary artery disease (ESCAD) patients the effects of on-pump/beating-heart versus conventional coronary artery bypass grafting (CABG) requiring cardioplegic arrest. We report early and midterm survival, morbidity, and improvement of left ventricular (LV) function. Between January 1992 and October 1999, 107 (Group I) ESCAD patients underwent on-pump/beating-heart surgery and 191 (Group II) ESCAD patients underwent conventional CABG requiring cardioplegic arrest. Mean age in Group I was 65.8 +/- 6.5 years (58-79 years); New York Heart Association (NYHA) and Canadian Cardiovascular Society (CCS) classifications were 3.2 +/- 0.4 and 3.3 +/- 0.5, respectively. LV ejection fraction (LVEF) was 24.8% +/- 4%, LV end diastolic pressure (LVEDP) was 28.2 +/- 3.8 mmHg, and LV end diastolic diameter (LVEDD) was 69.6 +/- 4.6 mm. Mean age in Group II was 64.1 +/- 5 years (57-76 years), NYHA class was 3 +/- 0.6, CCS class was 3.4 +/- 0.4, LVEF was 26.2% +/- 4.3%, LVEDP was 27.2 +/- 3.4 mmHg, and LVED was 68 +/- 4.2 mm. Preoperatively, Group I patients versus Group II patients had a markedly depressed LV function (LVEF, p = 0.006; LVEDP, p = 0.02; LVEDD, p = 0.003; and NYHA class, p = 0.002), older age (p = 0.012), and higher incidences of multiple acute myocardial infarction (AMI; p = 0.004), cardiovascular disease (CVD; p = 0.008), and chronic renal failure (CRH, p = 0.002). Cardiopulmonary bypass (CPB) time was longer in Group II patients (p = 0.028). The mean distal anastomosis per patient was similar between groups (p = NS). Operative mortality between Groups I and II was 7 (6.5%) and 19 (10%), respectively (p = NS). Perioperative AMI (p = 0.034), low cardiac output syndrome (LCOS; p = 0.011), necessity for ultrafiltration (p = 0.017), and bleeding (p = 0.012) were higher in Group II. Improvement of LV function within 3 months after the surgical procedure was markedly higher in Group I, demonstrated by increased LVEF (p = 0.035), lower LVEDP (p = 0.027), and LVEDD (p = 0.001) versus the preoperative data in Group II. The actuarial survivals at 1, 3, and 5 years were 95%, 86%, and 73% in Group I and 95%, 84%, and 72% in Group II (p = NS). ESCAD patients with bypassable vessels to two or more regions of reversible ischemia can undergo safe CABG with acceptable hospital survival and mortality and morbidity. In higher risk ESCAD patients, who may poorly tolerate cardioplegic arrest, on-pump/beating-heart CABG may be an acceptable alternative associated with lower postoperative mortality and morbidity. Such a technique offers better myocardial and renal protection associated with lower postoperative complications.