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Objectives: Postoperative pulmonary complications increase mortality, length, and cost of hospitalization. A better diaphragmatic strength may help face an increased work of breathing postoperatively. We, therefore, sought to determine if a low preoperative diaphragm thickening fraction (TFdi) determined by ultrasonography helped predict the occurrence of postoperative pulmonary complications after cardiac surgery independently of indicators of frailty, sarcopenia, and pulmonary function.Design: Prospective observational cohort study.Setting: Montreal Heart Institute, an academic cardiac surgery center in Canada.Patients: Adults undergoing nonemergency cardiac surgery.Interventions: We measured the preoperative thickness of the right and left hemidiaphragms at their zone of apposition at end-expiration (Tdi,ee) and peak-inspiration (Tdi,ei) with ultrasonography. Maximal thickening fraction of the diaphragm during inspiration (TFdi,max) was calculated using the following formula: TFdi,max = (Tdi,ei-Tdi,ee)/Tdi,ee. We also evaluated other potential risk factors including demographic parameters, comorbidities, Clinical Frailty Scale, grip strength, 5-meter walk test, and pulmonary function tests. We repeated TFdi,max measurements within 24 hours of extubation. The primary composite outcome of this study was the occurrence of postoperative pulmonary complications, defined as pneumonia, clinically significant atelectasis, or prolonged mechanical ventilation (> 24 hr).Measurement and Main Results: Of the 115 patients included, 34 (29.6%) developed postoperative pulmonary complications, including two with pneumonia, four with prolonged mechanical ventilation, and 32 with clinically significant atelectasis. Those with postoperative pulmonary complications had prolonged ICU and hospital length of stays. They had a lower TFdi,max (37% [interquartile range, 31-45%] vs 44% [interquartile range, 33-58%]; p = 0.03). In multiple logistic regression, a TFdi,max less than 38.1% was associated with postoperative pulmonary complications (odds ratio, 4.9; 95% CI, 1.81-13.50; p = 0.002). All patients who developed pneumonia or prolonged mechanical ventilation had a TFdi,max less than 38.1%. Respiratory rate and diabetes were also independently associated with postoperative pulmonary complications, while pulmonary function tests and the assessed indicators of frailty and sarcopenia were not.Conclusions: A low preoperative TFdi,max can help to identify patients at increased risk of postoperative pulmonary complications after cardiac surgery. [ABSTRACT FROM AUTHOR]

Background: Pulmonary vein (PV) stenosis is a complication of atrial fibrillation (AF) ablation. The incidence of PV stenosis after routine post-ablation imaging remains unclear and is limited to single-centre studies. Our objective was to determine the incidence and predictors of PV stenosis following circumferential radiofrequency ablation in the multicentre Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination (ADVICE) trial., Methods: Patients with symptomatic AF underwent circumferential radiofrequency ablation in one of 13 trial centres. Computed tomographic (CTA) or magnetic resonance (MRA) angiography was performed before ablation and 90 days after ablation. Two blinded reviewers measured PV diameters and areas. PVs with stenosis were classified as severe (> 70%), moderate (50%-70%), or mild (< 50%). Predictors of PV stenosis were identified by means of multivariable logistic regression., Results: A total of 197 patients (median age 59.5 years, 29.4% women) were included in this substudy. PV stenosis was identified in 41 patients (20.8%) and 47 (8.2%) of 573 ablated PVs. PV stenosis was classified as mild in 42 PVs (7.3%) and moderate in 5 PVs (0.9%). No PVs had severe stenosis. Both cross-sectional area and diameter yielded similar classifications for severity of PV stenosis. Diabetes was associated with a statistically significant increased risk of PV stenosis (OR 4.91, 95% CI 1.45-16.66)., Conclusions: In the first systematic multicentre evaluation of post-ablation PV stenosis, no patient acquired severe PV stenosis. Although the results are encouraging for the safety of AF ablation, 20.8% of patients had mild or moderate PV stenosis, in which the long-term effects are unknown., (Copyright © 2020 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Background: Anemia is associated with an increased risk of death in heart failure (HF) patients. Currently, the relationship between temporal variations in hematocrit and specific causes of mortality and morbidity, as well as the most appropriate way to monitor changes in hematocrit, is unknown., Objective: To evaluate the prognostic value of changes in hematocrit during follow-up on specific causes of mortality and morbidity in the Studies Of Left Ventricular Dysfunction (SOLVD)., Methods: A retrospective analysis of the SOLVD trials was conducted. Changes in hematocrit were evaluated in two ways: hematocrit as an absolute value at baseline and at each visit, and relative hematocrit variations compared with baseline., Results: Low absolute hematocrit values during follow-up were associated with cardiovascular (CV), non-CV and HF mortality, HF and non-CV hospitalizations, and cardiac ischemic events (P<0.05 for all end points). Decreases in hematocrit during follow-up compared with baseline were associated with HF hospitalizations (P<0.05) and non-CV death in patients receiving placebo (P=0.01 for interaction)., Conclusions: Hematocrit values during follow-up provide independent prognostic information in patients with HF for both CV and non-CV events. Absolute values of hematocrit are more closely related with outcomes and are therefore more clinically relevant to monitor than relative variations.

Background: Atrial fibrillation (AF) is frequently encountered in patients with heart failure (HF) and is also a predictor of morbidity and mortality in this population. Recent experimental studies have shown electrical and structural atrial remodeling with increased fibrosis in animals with HF and have suggested a preventive effect of ACE inhibitors (ACEi) on the development of AF. To verify the hypothesis that ACEi prevent the development of AF in patients with HF, we conducted a retrospective analysis of the patients from the Montreal Heart Institute (MHI) included in the Studies Of Left Ventricular Dysfunction (SOLVD)., Methods and Results: Clinical charts were reviewed and serial ECGs interpreted by a single cardiologist blinded to drug allocation. Patients with AF or flutter on the baseline ECG were excluded. Baseline characteristics were obtained from the SOLVD databases. The mean follow-up was 2.9+/-1.0 years. Of the 391 patients randomly assigned at MHI, 374 were in sinus rhythm at the time of random assignment, with 186 taking enalapril and 188 taking placebo. Baseline characteristics were similar in the two groups except for a higher incidence of previous myocardial infarction in the enalapril group. Fifty-five patients had AF during the follow-up: 10 (5.4%) in the enalapril group and 45 (24%) in the placebo group (P<0.0001). By Cox multivariate analysis, enalapril was the most powerful predictor for risk reduction of AF (hazard ratio, 0.22; 95% CI, 0.11 to 0.44; P<0.0001)., Conclusions: Treatment with the ACEi enalapril markedly reduces the risk of development of atrial fibrillation in patients with left ventricular dysfunction.

Background and Objectives: Several studies suggested that the insulin resistance-associated metabolic syndrome (MS) is a major risk factor for coronary artery disease (CAD), but the criteria to identify MS were only recently standardized by the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III., Methods: We evaluated the incidence of the newly defined MS in patients with documented CAD and compared the characteristics of patients with and without this syndrome., Results: In a Canadian population with CAD (793 men and 315 women, age 58.1+/-9.8 years) 51% had MS. As compared to patients without the MS syndrome, these patients had significantly higher waist circumference, blood pressure levels and fasting glucose and triglyceride, but lower high-density lipoprotein (HDL)-cholesterol levels. Their homeostatic model assessment (HOMA) insulin resistance index was significantly higher, with indicators of highly atherogenic, small low-density lipoprotein (LDL) and HDL particles. Family history of diabetes and the use of hypoglycemic agents, beta-blockers and thiazides were more frequent, but physical exercise and alcohol consumption were less frequent in MS positive patients. Cumulative coronary stenosis score and the frequency of patients with >50% coronary artery narrowing were higher and there was a strong tendency for higher rates of previous myocardial infarction in MS positive patients., Conclusions: In a CAD population documented in 1991-1992, 51% of participants had MS and in several respects a more advanced coronary disease than those without the syndrome. These results support the view of NCEP ATP III, that in CAD prevention, beyond lowering LDL-cholesterol levels, interventions concerning the constituents of MS should be important.