Pulse pressure and risk of adverse outcome in coronary bypass surgery

Abstract

Background: Among ambulatory patients, an increase in pulse pressure (PP) is a well-established determinant of vascular risk. The relationship of PP and acute perioperative vascular outcome among patients having coronary artery bypass graft (CABG) surgery is less well known.

Methods: We conducted a prospective observational study involving 5436 patients having elective CABG surgery requiring cardiopulmonary bypass. Of these, 4801 met final inclusion criteria. Comprehensive data were captured for medical history, intraoperative and postoperative physiologic and laboratory measures, diagnostic testing, and clinical events. The relationship between preoperative hypertension (systolic, diastolic, PP) and ischemic cardiac and cerebral outcomes and death was assessed using multivariable logistic regression; P<0.05 was considered significant.

Results: Nine hundred and seventeen patients (19.1%) had fatal and nonfatal vascular complications, including 146 patients (3.0%) with cerebral and 715 patients (14.9%) with cardiac events. In-hospital mortality occurred in 147 patients (3.1%). Among all blood pressure variables measured preoperatively, PP was most strongly associated with an increased risk of postoperative complications. PP increments of 10 mm Hg (above a threshold of 40 mm Hg) were associated with an increased risk of cerebral events (adjusted odds ratio: 1.12; 95% CI [1.002-1.28]; P=0.026). The incidence of a cerebral event and/or death from neurologic complications nearly doubled for patients with PP>80 mm Hg versus<or=80 mm Hg (5.5% vs 2.8%; P=0.004). PP more than 80 mm Hg was also found to be associated with cardiac complications, increasing the incidence of congestive heart failure by 52%, and death from cardiac cause by nearly 100% (P=0.003 and 0.006, respectively).

Conclusion: An increase in PP was independently and significantly associated with greater fatal and nonfatal adverse cerebral and cardiac outcomes in patients having CABG surgery. These findings highlight the associated risks of preoperative PP on acute postoperative vascular outcomes.