Marco Zanobini

Atrial fibrillation after isolated coronary surgery affects late survival.

Background— Atrial fibrillation (AF) after coronary artery bypass graft surgery is a difficult problem and a continuing source of morbidity and mortality. However, the prognostic implications of postoperative AF are still in dispute. Our aim was to ascertain the impact of AF after coronary artery bypass graft on postoperative survival and to assess its prognostic role in cause-specific mortality. Methods and Results— We conducted a prospective observational study of 1832 patients undergoing isolated coronary artery bypass graft between January 2000 and December 2005 at 2 cardiac surgery centers in northern Italy. Patients affected by postoperative AF were identified and followed up until death or study end (April 30, 2007). A total of 570 patients (31%) developed AF after coronary surgery. Patients affected by postoperative AF experienced a longer hospital stay (7 days [25th to 75th percentile, 7 to 10 days] versus 7 days [25th to 75th percentile, 6 to 8 days]; P<0.001). Hospital mortality also was higher in AF patients (3.3% versus 0.5%; P<0.001). On discharge, 1806 patients were alive; 143 were lost to follow-up. The remaining 1663 were followed up for a median of 51 months (25th to 75th percentile, 41 to 63 months); 126 of them died after a median of 14 months (25th to 75th percentile, 5 to 32 months). Long-term mortality rates were significantly higher for patients with postoperative AF (2.99 per 100 person-years; 95% confidence interval, 2.33 to 3.84; 61 deaths) compared with those without the arrhythmia (1.34 per 100 person-years; 95% confidence interval, 1.05 to 1.71; 65 deaths), with an adjusted hazard ratio of 2.13 (P<0.001) and 2.56 (P=0.001) when also accounting for the prescription of warfarin at discharge. With Cox regression, patients with AF were shown to be at higher risk of dying from embolism (adjusted hazard ratio, 4.33; 95% confidence interval, 1.78 to 10.52) but not from other causes. Conclusions— Postoperative AF affects early and late mortality after isolated coronary artery bypass graft surgery. Patients affected by AF are at higher risk of fatal embolic events. Careful postoperative surveillance with a specific antiarrhythmic and antithrombotic prophylaxis, aimed at reducing AF and its complications, is recommended.

Biological effects of off-pump vs. on-pump coronary artery surgery: focus on inflammation, hemostasis and oxidative stress

Cardiopulmonary bypass (CPB) has been recognized as a cause of complex systemic inflammatory response, which significantly contributes to several adverse postoperative complications. In the last few years, off-pump coronary artery bypass grafting has gained widespread diffusion as an alternative technique to conventional on-pump coronary artery bypass grafting. Surgeons supporting off-pump surgery state that the avoidance of the CPB and myocardial ischemia-reperfusion significantly reduces the postoperative systemic inflammatory response and other biological derangements and, possibly, may improve the clinical outcomes. We review, here, the available evidence concerning possible differences between off-pump and on-pump procedures in terms of inflammation, hemostasis and oxidative stress. Consistent differences in the involvement of these systems are observed, but they are limited to the final steps of the surgical procedures and the early hours after. These findings suggest that the global surgical trauma may be as important, or even more, as the CPB in terms of systemic inflammatory and coagulation-fibrinolytic pathway activation. Further studies are needed in order to confirm this hypothesis.

The radial artery: which place in coronary operation?

Previous long-term studies have shown unsatisfactory patency of saphenous vein grafts, compared with internal mammary artery grafts. Recently, the use of the radial artery as a coronary artery bypass graft has enjoyed a revival, on the basis of the belief that it will help improving long-term results of coronary operations. The recent report of encouraging 5-year patency rates, supports its continued use as a bypass graft. In this paper, we review the current knowledge about the radial artery as a bypass graft, with special emphasis on the clinical results.

The mitochondrial lncRNA ASncmtRNA-2 is induced in aging and replicative senescence in Endothelial Cells

Age-associated cardiovascular diseases are at least partially ascribable to vascular cell senescence. Replicative senescence (RS) and stress-induced premature senescence (SIPS) are provoked respectively by endogenous (telomere erosion) and exogenous (H2O2, UV) stimuli resulting in cell cycle arrest in G1 and G2 phases. In both scenarios, mitochondria-derived ROS are important players in senescence initiation. We aimed to define whether a mtDNA-transcribed long-non-coding-RNA (lncRNA), ASncmtRNA-2, has a role in vascular aging and senescence. Aortas of old mice, characterized by increased senescence, showed an increment in ASncmtRNA-2 expression. In vitro analysis of Endothelial Cells (EC) and Vascular Smooth Muscle Cells (VSMC) established that ASncmtRNA-2 is induced in EC, but not in VSMC, during RS. Surprisingly, ASncmtRNA-2 is not upregulated in two different EC SIPS scenarios, treated with H2O2 and UV. The p16 gene displayed similar ASncmtRNA-2 expression patterns, suggesting a possible co-regulation of the two genes. Interestingly, the expression of two miRNAs, hsa-miR-4485 and hsa-miR-1973, with perfect homology to the double strand region of ASncmtRNA-2 and originating at least in part from a mitochondrial transcript, was induced in RS, opening to the possibility that this lncRNA functions as a non-canonical precursor of these miRNAs. Cell cycle analysis of EC transiently over-expressing ASncmtRNA-2 revealed an accumulation of EC in the G2/M phase, but not in the G1 phase. We propose that ASncmtRNA-2 in EC might be involved in the RS establishment by participating in the cell cycle arrest in G2/M phase, possibly through the production of hsa-miR-4485 and hsa-miR-1973. This article is part of a Special Issue entitled: Mitochondria.

Preoperative Statin Therapy Is Not Associated With a Decrease in the Incidence of Delirium After Cardiac Operations

BACKGROUND Delirium after cardiac operations is associated with significant morbidity and death. Statins have been recently suggested to exert protective cerebral effects. This study investigated whether preoperative statins were associated with decreased incidence of postoperative delirium in patients undergoing coronary artery bypass grafting. METHODS The study enrolled 4,659 consecutive patients (21% women; age, 67.8±9.2 years) undergoing coronary artery bypass grafting. A propensity score-based optimal-matching algorithm was used to match 1,577 patients receiving preoperative statins with a control group (1:1). Patients were screened for delirium in the intensive care unit according to the Confusion Assessment Method for the intensive care unit. RESULTS Delirium affected 89 patients (3%), and preoperative statin administration was not multivariably associated with a decreased incidence of delirium (odds ratio, 1.52; 95% confidence interval, 0.97 to 2.37; p=0.18) and was also unrelated to a delirium decrease in patient subgroups undergoing isolated coronary artery bypass grafting (odds ratio, 1.31; 95% confidence interval, 0.68 to 2.52; p=0.51) or combined valvular procedures (odds ratio, 1.72; 95% confidence interval, 0.96 to 3.07, p=0.08). Similar results were observed for age groups and cardiopulmonary bypass durations. Patients affected by postoperative delirium experienced a longer hospital stay (25th to 75th percentile) of 11 (7 to 18 days) vs 7 days (7 to 8 days, p<0.001) and 12% hospital mortality vs 1% (p<0.001). CONCLUSIONS Preoperative statins were not associated with a decreased incidence of delirium in patients undergoing coronary revascularization.

Evaluation of Right Ventricular Systolic Function after Mitral Valve Repair: A Two-Dimensional Doppler, Speckle-Tracking, and Three-Dimensional Echocardiographic Study

BACKGROUND Conventional indices of right ventricular (RV) function are known to be reduced after cardiac surgery, as a consequence of geometric rather than functional alterations. New techniques, such as three-dimensional (3D) transthoracic and two-dimensional speckle-tracking echocardiography, may be useful in postsurgical RV assessment. The aim of this study was to compare indices of RV function obtained using different echocardiographic modalities, before and after surgery. METHODS Forty-two patients were screened the day before and 6 months after mitral valve repair. Twenty healthy patients were also enrolled as controls. Tricuspid annular plane systolic excursion and peak systolic velocity were calculated from Doppler tissue imaging. Longitudinal and radial strain values were obtained from speckle-tracking echocardiography. RV ejection fraction was calculated from 3D transthoracic echocardiographic RV volumes, and similarly, fractional area change was computed from RV areas. RESULTS Tricuspid annular plane systolic excursion (25 ± 4 vs 17 ± 3 mm), peak systolic velocity (17 ± 4 vs 12 ± 2 cm/sec), and fractional area change (43 ± 8% vs 39 ± 7%) significantly decreased after surgery (P < .01), while 3D RV ejection fraction was preserved (59 ± 7% vs 59 ± 6%). Speckle-tracking echocardiographic results were dependent on the considered direction, with preserved radial but decreased longitudinal strain values. All postoperative two-dimensional longitudinal indices were smaller than in controls. Preoperative parameters were not significantly correlated with RV functional changes. CONCLUSIONS Although 3D ejection fraction was preserved after surgery, in agreement with the lack of evidence of RV dysfunction, two-dimensional indices showed a functional loss in the longitudinal direction. Fractional area change, as a combination of radial and longitudinal properties, was slightly decreased. Speckle-tracking echocardiography could constitute a useful approach to relate local and space-dependent changes to the global RV function.

Lack of Association Between Serum Immunoreactivity and Chlamydia pneumoniae Detection in the Human Aortic Wall

Background—Only a few studies have focused the attention on the relation between elevated anti–Chlamydia pneumoniae (CP) antibodies and the detection of CP in the arterial wall. The aim of our study is thus to investigate the relationship between immune response to CP and detection of CP in the aortic walls of patients with abdominal aortic aneurysm. Methods and Results—A specimen of aortic wall was obtained from 102 consecutive patients who underwent abdominal aneurysm repair. The possible presence of CP was studied by polymerase chain reaction and confirmed by nonradioactive DNA hybridization. Antibody response to CP was studied (IgG, IgA titers). We found 33 patients (32.4%) with CP DNA+. No correlation between CP DNA detection and antibody titers was found (IgG P =0.52, IgA P =0.66). High correlation between IgG and IgA titer was observed (P <0.01). Endovascular presence of CP and antibody titers was not related to the age of the patient. Conclusions—CP antibody titers are not associated with the presence of CP in the aortic wall of patients with abdominal aortic aneurysm.

Pre-operative transthoracic real-time three-dimensional echocardiography in patients undergoing mitral valve repair: accuracy in cases with simple vs. complex prolapse lesions

AIMS The aim of this study, undertaken in patients who underwent mitral valve (MV) repair surgery, was to evaluate the accuracy of pre-operative three-dimensional (3D) transthoracic echocardiography (TTE) in the evaluation of MV pathology in cases with simple or complex lesions. METHODS AND RESULTS Two hundred consecutive patients with severe mitral regurgitation due to degenerative MV prolapse underwent a complete 3DTTE the day before surgery. Three-dimensional TTE data were compared with MV surgical inspection. Three-dimensional echocardiography was feasible in a relatively short time (5 ± 3 min) with good (67%) and optimal (21%) imaging quality in the majority of cases. Three-dimensional TTE allowed an accurate identification (95% accuracy) of all MV lesions. Seventy-three (36.5%) patients had simple lesions at 3DTTE and 71 of them (97.2%) underwent a simple surgical procedure; 127 (63.5%) had complex lesions at 3DTTE and, in these cases, surgeons performed either simple procedures (48%) or complex procedures (47.2%) or valve replacement in 4.7% (after a first attempt for repair). CONCLUSION Three-dimensional TTE is feasible, not time-consuming, and accurate in identifying cases with simple vs. complex MV lesions.

Reliability of new scores in predicting perioperative mortality after isolated aortic valve surgery: A comparison with the society of thoracic surgeons score and logistic EuroSCORE

BACKGROUND There is still a wide debate concerning the performance of commonly used risk prediction models in assessing the risk of patients undergoing isolated aortic valve surgery. This study was designed to compare the performances of European System for Cardiac Operative Risk Evaluation (EuroSCORE) II and age, creatinine, and ejection fraction (ACEF) score with those of The Society of Thoracic Surgeons (STS) score and logistic EuroSCORE in patients undergoing isolated aortic valve surgery. METHODS Data on 1,758 consecutive patients who underwent isolated aortic valve replacement in a 6-year period were retrieved from 3 prospective institutional databases. Discriminatory power was assessed using the c-index. Calibration was evaluated with calibration curves and associated statistics. RESULTS In-hospital mortality rate was 1.4%. The discriminatory power was similar in all algorithms (area under the curve 0.80, 95% confidence interval [CI] 0.72 to 0.88 for logistic EuroSCORE; 0.81, 95% CI 0.73 to -0.88 for EuroSCORE II; 0.78, 95% CI 0.68 to 0.88 for ACEF; 0.85, 95% CI 0.78-0.93 for STS score) and not significantly different (p values > 0.05 for all tests). The EuroSCORE II had a better calibration, being the only score with nonsignificant associated statistics (unreliability test, Hosmer-Lemeshow test, and Spiegelhalter Z-test for calibration accuracy). Nonetheless, EuroSCORE II calibration plot highlighted a trend over under-prediction. CONCLUSIONS The EuroSCORE II is a good predictor of perioperative mortality in isolated aortic valve surgery, with lower discrimination if compared with STS and a better calibration when compared with logistic EuroSCORE, ACEF, and STS scores. Its performance is optimal in the lowest tertile of patients, whereas it under-predicts mortality afterward. None of these algorithms seems suitable for risk estimation in mid and high-risk patients that are the ones who might benefit most from transcatheter procedures.

Bedside Tool for Predicting the Risk of Postoperative Atrial Fibrillation After Cardiac Surgery: The POAF Score

Background Atrial fibrillation (AF) remains the most common complication after cardiac surgery. The present study aim was to derive an effective bedside tool to predict postoperative AF and its related complications. Methods and Results Data of 17 262 patients undergoing adult cardiac surgery were retrieved at 3 European university hospitals. A risk score for postoperative AF (POAF score) was derived and validated. In the overall series, 4561 patients (26.4%) developed postoperative AF. In the derivation cohort age, chronic obstructive pulmonary disease, emergency operation, preoperative intra‐aortic balloon pump, left ventricular ejection fraction <30%, estimated glomerular filtration rate <15 mL/min per m2 or dialysis, and any heart valve surgery were independent AF predictors. POAF score was calculated by summing weighting points for each independent AF predictor. According to the prediction model, the incidences of postoperative AF in the derivation cohort were 0, 11.1%; 1, 20.1%; 2, 28.7%; and ≥3, 40.9% (P<0.001), and in the validation cohort they were 0, 13.2%; 1, 19.5%; 2, 29.9%; and ≥3, 42.5% (P<0.001). Patients with a POAF score ≥3, compared with those without arrhythmia, revealed an increased risk of hospital mortality (5.5% versus 3.2%, P=0.001), death after the first postoperative day (5.1% versus 2.6%, P<0.001), cerebrovascular accident (7.8% versus 4.2%, P<0.001), acute kidney injury (15.1% versus 7.1%, P<0.001), renal replacement therapy (3.8% versus 1.4%, P<0.001), and length of hospital stay (mean 13.2 versus 10.2 days, P<0.001). Conclusions The POAF score is a simple, accurate bedside tool to predict postoperative AF and its related or accompanying complications.