Coronary artery disease (CAD) is one of the leading causes of death and disability in Europe and worldwide. For patients with multi-vessel CAD, coronary artery bypass graft (CABG) surgery is a common approach for coronary revascularization, and is of proven symptomatic and prognostic benefit. Due to an aging population, higher prevalence of co-morbidities (such as diabetes mellitus, heart failure, hypertension, and renal failure), and a growing requirement for concomitant surgical procedures (such as valve and aortic surgery), higher risk patients are undergoing surgery. ^1–3 This has resulted in an increased risk of peri-operative myocardial injury (PMI) ⁴ and Type 5 myocardial infarction (MI), both of which are associated with worsened clinical outcomes following CABG surgery. The aetiology and determinants of PMI and Type 5 MI are multi-factorial (see Tables 1 and 2 for summary). Although diagnostic criteria have been proposed for Type 5 MI (based on an elevation in cardiac biomarkers in the 48-h post-operative period and electrocardiogram/angiography/imaging evidence of MI ^{5, 13}), there is currently no clear definition for prognostically significant PMI, in terms of the level of post-operative cardiac biomarker elevation, which is associated with worsened clinical outcomes following CABG surgery.

The sequential, staged hybrid approach has recently emerged as a novel strategy for the treatment of long-standing persistent atrial fibrillation (AF); nevertheless, the potential modifications in terms of electrophysiological findings and their correlation with mid-term results have not been fully elucidated so far. Forty-five patients with long-standing persistent AF underwent a hybrid procedure combining surgical closed-chest posterior left atrium (LA) and pulmonary veins (PV) isolation (box lesion) first, followed by transcatheter evaluation at least 1 month afterwards. Electrophysiological findings and their correlation with rhythm outcomes were assessed at different time points, i.e. following the surgical ablation (T1), during (T2) and at the end (T3) of the transcatheter evaluation and at 28-month follow-up (T4). At T1, exit and entrance blocks were achieved in 100 and 91.1% (41 of 45) of patients, respectively. At T2, the percentage of conduction block was unchanged, while at T3 also entrance block was achieved in all instances. In terms of electrophysiological findings (at T2), PV reconnection occurred in 6.7% (3 of 45) of patients, fractionated electrograms were targeted in 44.4% (20 of 45) while right atrium isthmus lesion was performed in 24.4% (11 of 45) of patients. Sinus rhythm was restored in 75.6% (34 of 45) at T1, at T2 (with AF induction) in 68.9% (31 of 45), at T3 in 93.3% (42 of 45) and at T4 in 88.9% (40 of 45) of patients, respectively. In those patients with a bidirectional block at T1, sinus rhythm restoration steadily improved from 78 (32 of 41) at T1 to 82.9 (34 of 41) at T2 and finally 92.6% (38 of 41) at T4. Complete posterior LA and PV isolation with the box lesion in a staged hybrid approach is associated with incremental benefits in terms of sinus rhythm maintenance in patients with long-standing persistent AF.