Predictors of cerebrovascular accident and transient ischemic attack after myocardial revascularisation

Objective

To analyze the occurrence of postoperative neurological complications, defined as cerebrovascular accident (CVA) and transient ischemic attack (TIA), after myocardial revascularisation, in relation to pre- and perioperative variables.

Methods

We analyzed the pre-, peri-, and postoperative data of 3834 patients who underwent primary isolated bypass grafting between January 1987 and December 1995. Unifactor risk analysis was used to identify which of the variables was a risk factor for neurological complications. Which of these variables contribute independently was analysed using multifactor risk regression analysis. A χ² test was used to identify which independent predictor changed with time. The studied period of 9 years was divided into three time cohorts of 3 years each.

Results

The incidence of neurological complications was 32/3834 patients (0.8%), and increased from 0.6% over 0.8% to 1.1% during studied period. Unifactor analysis identified the following as risk factors: age > 75 years(P = 0.008), peripheral vascular atherosclerosis or operation (carotid; P = 0.002), preoperative neurological pathology (P = 0.003), perioperative detected aortapathology (P < 0.0001) and perioperative myocardial infarction (P = 0.01). Multifactor risk regression analysis identified preoperative neurological pathology (P = 0.02), perioperative detected aortic pathology (P = 0.0001), and a perioperative myocardial infarction (P = 0.04) as independent predictors for postoperative neurological complications. In the three time cohorts there was a statistically significant change of prevalence for preoperative neurological pathology (P = 0.02) and perioperatively detected aortic pathology (P = 0.001).

Conclusion

Preoperative neurological pathology, perioperative myocardial infarction, but primarily aortapathology were identified as independent risk factors for postoperative CVA and/or TIA after myocardial revascularization. On the basis of these results the use of transoesophageal echocardiography for detection of aorta pathology in risk patients and single aorta cross-clamping should be strongly advised.