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The debate on the advantages and limitations of off-pump (OP) vs on pump (ON) CABG has not still arrived to a conclusion and concerns still exist on graft patency. Aim of this study was to compare the impact of OPCABG and ONCABG on mortality and morbidity, with a specific focus on mid-term need for percutaneous cardiac intervention (PCI).
The PRIORITY study is designed to evaluate mid and long term outcomes in a cohort of patients undergoing a CABG intervention in 2004 and between 2007-2008 in some Italian Cardiac Surgery Centers. Data on isolated OP and ON CABG interventions were derived from the study clinical dataset while follow-up information were derived from the national registry of Hospital Discharge Records collected in Italy from 2004 to 2012, linked with the national Tax registry. The time-to-event distributions were compared separately according to primary event-type (death or hospitalization for PCI), using the Cox regression for the time-to-death analysis and the competing risk analysis for time-to-PCI, with death as competing risk.
The PRIORITY population consisted of 11020 patients who underwent isolated CABG (27.2% performed OP). The follow-up time ranged from 4 to 10 years. Although unadjusted long-term survival was significantly worst for OP CABG, the adjustment did not confirm OP CABG as a risk factor for mortality (hazard ratio = 0.96, p-value= 0.407). The incidence of postoperative PCI was significantly higher in OP than in the ON CABG group (2.64% vs 0.98%; p-value <0.0001). The significantly better cumulative incidence function of hospitalization for PCI at follow-up in the ON CABG group was confirmed even by the adjustment for confounding factors (ON CABG adjusted hazard ratio = 0.70; 95% CI= 0.62-0.80). Hence, ON CABG represents an independent protective factor for recurrent PCI after CABG.
This study demonstrated that the surgical technique used to perform a CABG intervention does not affect mid-long-term mortality. Nonetheless, ON CABG showed to be an independent risk factor for patients’ later PCI.