Determinants of maximal oxygen uptake in patients with heart failure.

AIMS: Maximum oxygen uptake (VO2max ) is an essential parameter to assess functional capacity of patients with heart failure (HF). We aimed to identify clinical factors that determine its value, as they have not been well characterized yet. METHODS: We conducted a retrospective, observational, single-centre study of 362 consecutive patients with HF who underwent cardiopulmonary exercise testing (CPET) as part of standard clinical assessment since 2009-2019. CPET was performed on treadmill, according to Bruce's protocol (n = 360) or Naughton's protocol (n = 2). We performed multivariable linear regression analyses in order to identify independent clinical predictors associated with peak VO2max . RESULTS: Mean age of study patients was 57.3 ± 10.9 years, mean left ventricular ejection fraction was 32.8 ± 14.2%, and mean VO2max was 19.8 ± 5.2 mL/kg/min. Eighty-nine (24.6%) patients were women, and 114 (31.5%) had ischaemic heart disease. Multivariable linear regression analysis identified six independent clinical predictors of VO2max , including NYHA class (B coefficient = -2.585; P < 0.001), age (B coefficient per 1 year = -0.104; P < 0.001), tricuspid annulus plane systolic excursion (B coefficient per 1 mm = +0.209; P < 0.001), body mass index (B coefficient per 1 kg/m2  = -0.172; P = 0.002), haemoglobin (B coefficient per 1 g/dL = +0.418; P = 0.007) and NT-proBNP (B coefficient per 1000 pg/mL = -0.142; P = 0.019). CONCLUSIONS: The severity of HF (NYHA class, NT-proBNP) as well as age, body composition and haemoglobin levels influence significantly exercise capacity. In patients with HF, the right ventricular systolic function is of greater importance for the physical capacity than the left ventricular systolic function.

Surgical technique modifies the postoperative atrioventricular block rate in sutureless prostheses.

BACKGROUND: The main objective was to analyse the impact of the modification of the Perceval S implantation technique on the prevalence of postoperative atrioventricular block, which requires a permanent pacemaker, in our aortic valve replacement series. In addition, we attempted to identify those risk factors that are related to the appearance of this complication. METHODS: Five hundred and seventy-two valve replacements were carried out with PERCEVAL S in our centre up to July 2018. Use of modified technique (n=302). Minimally invasive approach (n=340). Associated coronary surgery (n=95). Patients with pacemakers prior to surgery (n=27) and associated mitral or tricuspid valve surgery (n=26) were excluded. We analysed variables of interest that could influence the increase in postoperative atrioventricular block. Technique performed, disorders of intraventricular conduction and pre/intraoperative characteristics. The influence of the modified technique was analysed. RESULTS: Five hundred and nineteen aortic valve replacements with PERCEVAL S. Age (years) (median 77, interquartile range 8). Height (cm) (159, 13.5). Euroscore II (%) (2.25, 2.27). Postoperative atrioventricular block standard technique (n=23, 10.14%). Modified technique (n=14, 4.30%) (P=0.009). Multivariate regression analysis. Final model AUC =0.740, maximum model AUC =0.774 (P>0.05). Includes: Technique used (P=0.024), height (P=0.043) and disorders of interventricular conduction, right bundle branch block (P=0.005), trifascicular block (P=0.008). CONCLUSIONS: In our experience, the modified technique significantly decreases the incidence of postoperative atrioventricular block that requires a permanent pacemaker in the aortic valve replacement with PERCEVAL S. The prior electrocardiographic presence of right bundle branch block, trifascicular block and the height of the patient are associated with an increased risk of blocking.