Mid- and long-term prognosis of off- vs. on-pump coronary artery bypass graft in patients with multisite artery disease

BACKGROUND

Among patients with coronary artery disease (CAD), around 25% have multisite artery disease (MSAD). Patients with CAD and MSAD are at higher risk of peri-operative and long-term cardiovascular events. Whether off-pump coronary bypass grafting (CABG) can improve their prognosis is unknown. We aimed to assess the benefits of off- vs. on-pump cardiac surgery in patients undergoing CABG, according to coexistence of extra-cardiac artery disease.

METHODS

Between April 1998 and September 2008, 1221 patients undergoing CABG without any other intervention were enrolled. Overall death and major cardiovascular events were recorded at 1-month and during long-term follow-up. A propensity score (PS), derived from all relevant variables (P<0.25) associated with on-pump as compared to off-pump CABG, and representing the likelihood for each individual patient to receive off-pump CABG, was calculated.

RESULTS

MSAD was observed in 279 patients (23%). Off-pump CABG was performed in 208 (17%) patients. The median follow-up was 7.6 years. The 10-year mortality was significantly lower in off- vs. on-pump CABG group (74±4% vs. 68±2%, P=0.024). In patients with MSAD, there was a trend for better survival for off- vs. on-pump CABG (63±8% vs. 50±4%, P=0.078). After adjustment for PS, we found no further difference between on- and off-pump CABG both in the whole cohort (HR=1.30, P=0.10), as well as in MSAD patients (HR=1.51, P=0.14).

CONCLUSIONS

Patients with MSAD receiving CABG are at worst prognostic than those with isolated CAD. In these patients, we found no significant difference in the long-term mortality and cardiovascular events between on- and off-pump CABG.

The intrinsic prognostic value of the ankle-brachial index is independent from its mode of calculation

The object of this study was to compare the prognostic value of different methods of ankle-brachial index (ABI) calculation. From April 1998 to September 2008, we calculated the ABI in 1223 patients before coronary artery bypass grafting. The ABI was calculated according to five different calculation modes of the numerator. The patients were classified into three groups: clinical peripheral artery disease (PAD), subclinical PAD if no clinical history but abnormal ABI (< 0.90 or > 1.40), and no PAD. The primary outcome was total mortality. During a follow-up of 7.6 years (0.1-15.9), 406 patients (33%) died. The prevalence of the subclinical PAD varied from 22% to 29% according to the different modes of ABI calculation. Areas under the ROC curve to predict mortality according to different calculation modes varied from 0.608 ± 0.020 to 0.625 ± 0.020 without significant differences. The optimal ABI threshold to predict mortality varied for every method, ranging from 0.87 to 0.95. In multivariate models, ABI was significantly and independently associated with total mortality (hazard ratio (HR) = 1.46, 95% CI: 1.15-1.85, p = 0.002); however, this association was not significantly different between the various methods (HRs varying from 1.46 to 1.67). The use of the optimal ABI threshold for each calculation mode (rather than standard 0.90) allowed a slight improvement of the model. In conclusion, the ABI prognostic value to predict mortality is independent from its method of calculation. The use of different optimal thresholds for each method enables a comparable prognosis value.