Should I Change to OPCAB?
Much is written about the benefits of off-pump coronary artery bypass surgery (OPCAB). Is it applicable to all practices? Does that mean we all need to change to OPCAB? The surgical literature appears to have flaws with regard to providing answers. In striving for evidence-based medicine, one could integrate clinical data with external best evidence or do proper power calculations to determine study sizes.
In a local, retrospective, observational study, 535 patients had a CABG done with the aid of cardiopulmonary bypass and cardiac arrest. Five hundred and seven patients were considered appropriate for analysis. Mortality was seven (1.4%), the prevalence of myocardial infarction four (0.8%), renal dialysis was four (0.8%) and stroke six (1.2%). Eighty (16%) patients required homologous blood transfusions. The median length of hospital stay was five days. If a local, randomised, controlled study was to be conducted to confirm an improvement with OPCAB, a large number of patients would be needed. For a 12.5% reduction in an event rate presently at 0.8%, 262 000 patients would be necessary. For a 50% reduction in an event rate presently at .0%, 2 300 patients should be recruited. The local prevalence rate is very low and the number of patients required for a series is too high. The supremacy of OPCAB for this practice is therefore not established.
