Anders Jeppsson

Background Cardiopulmonary bypass (CPB) ensures tissue oxygenation during cardiac surgery. New technology allows continuous registration of CPB variables during the operation. The aim of the present investigation was to study the association between CPB management and the risk of postoperative acute kidney injury (AKI). Methods This observational study based on prospectively registered data included 2661 coronary artery bypass grafting and/or valve patients operated during 2016–2020. Individual patient characteristics and postoperative outcomes collected from the SWEDEHEART registry were merged with CPB variables automatically registered every 20 s during CPB. Associations between CPB variables and AKI were analyzed with multivariable logistic regression models adjusted for patient characteristics. Results In total, 387 patients (14.5%) developed postoperative AKI. After adjustments, longer time on CPB and aortic cross‐clamp, periods of compromised blood flow during aortic cross‐clamp time, and lower nadir hematocrit were associated with the risk of AKI, while mean blood flow, bladder temperature, central venous pressure, and mixed venous oxygen saturation were not. Patient characteristics independently associated with AKI were advanced age, higher body mass index, hypertension, diabetes mellitus, atrial fibrillation, lower left ventricular ejection fraction, estimated glomerular filtration rate <60 or >90 mL/min/m 2 , and preoperative hemoglobin concentration below or above the normal sex‐specific range. Conclusions To reduce the risk of AKI after cardiac surgery, aortic clamp time and CPB time should be kept short, and low hematocrit and periods of compromised blood flow during aortic cross‐clamp time should be avoided if possible.

OBJECTIVES Current clinical guidelines have no specific recommendations regarding medical therapy after surgical aortic valve replacement in patients with aortic regurgitation (AR). We studied the association between medical therapy with renin–angiotensin system (RAS) inhibitors, statins and β-blockers and long-term major adverse cardiovascular events. METHODS All patients undergoing valve replacement due to AR between 2006 and 2017 in Sweden and alive 6 months after discharge were included. Time-dependent multivariable Cox regression models adjusted for age, sex, patient characteristics, comorbidities, other medications and year of surgical aortic valve replacement were used. Primary outcome was a composite of all-cause mortality, myocardial infarction and stroke. Subgroup analyses based on age, sex, heart failure, low ejection fraction, hyperlipidaemia and hypertension were performed. RESULTS A total of 2204 patients were included [median follow-up 5.0 years (range 0.0–11.5)]. At baseline, 68% of the patients were dispensed RAS inhibitors, 80% β-blockers and 35% statins. Dispense of RAS inhibitors and β-blockers declined over time, especially during the first year after baseline, while dispense of statins remained stable. Treatment with RAS inhibitors or statins was associated with a reduced risk of the primary outcome [adjusted hazard ratio (aHR) 0.71, 95% confidence interval (CI) 0.57–0.87 and aHR 0.78, 95% CI 0.62–0.99, respectively]. The results were consistent in subgroups based on age, sex and comorbidities. β-Blocker treatment was associated with an increased risk for the primary outcome (aHR 1.35, 95% CI 1.07–1.70). CONCLUSIONS The results indicate a potential beneficial association of RAS inhibitors and statins as part of a secondary preventive treatment regime after aortic valve replacement in patients with AR. The role of β-blockers needs to be further investigated.