Oldgren, Jonas

Background Sauna bath has potential as a lifestyle treatment modality for heart failure (HF). It is important to analyze the current evidence to help suggest paths of future study and potential for clinical application. Hypothesis Sauna bath has a positive effect on HF patients. Methods PubMed, Cochrane Library, and CINAHL databases were searched to identify randomized and nonrandomized controlled studies to compare effects of sauna bath with no sauna bath. Studies were searched for both infrared sauna bath and Finnish sauna bath. The strength of evidence was rated using a modified GRADE approach. Out of 1444 studies, nine met the inclusion criteria and were included in this review. Seven of these nine studies were included in the meta‐analysis. Only studies with infrared sauna bath met the inclusion criteria. Results In the meta‐analysis, exposure to an infrared sauna bath in 60°C for 15 minutes, followed by a 30‐minute rest in warm environment, five times a week for 2 to 4 weeks, was associated with a significant reduction in B‐type natriuretic peptide, cardiothoracic ratio, and an improvement in left‐ventricular ejection fraction. There was no significant effect on left‐ventricular end‐diastolic diameter, left atrial diameter, systolic blood pressure, or diastolic blood pressure. The strength of evidence varied from moderate to insufficient. Conclusion Infrared sauna bath was associated with short‐term improvement in cardiac function. More evidence is needed about long‐term effects of sauna bath and the effects of a Finnish sauna on cardiovascular health among patients with HF or other cardiovascular diseases.

Background Cardiac biomarkers are independent risk markers in atrial fibrillation, and the novel biomarker–based ABC stroke score (age, biomarkers, and clinical history of prior stroke) was recently shown to improve the prediction of stroke risk in patients with atrial fibrillation. Our aim was to investigate the short‐term variability of the cardiac biomarkers and evaluate whether the ABC stroke risk score provides a stable short‐term risk estimate. Methods and Results According to the study protocol, samples were obtained at entry and also at 2 months in 4796 patients with atrial fibrillation followed for a median of 1.8 years in the ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial. Cardiac troponin I, cardiac troponin T, and N‐terminal pro‐B‐type natriuretic peptide were measured with high‐sensitivity immunoassays. Associations with outcomes were evaluated by Cox regression. C indices and calibration plots were used to evaluate the ABC stroke score at 2 months. The average changes in biomarker levels during 2 months were small (median change cardiac troponin T +2.8%, troponin I +2.0%, and N‐terminal pro‐B‐type natriuretic peptide +13.5%) and within‐subject correlation was high (all ≥0.82). Repeated measurement of cardiac biomarkers provided some incremental prognostic value for mortality but not for stroke when combined with clinical risk factors and baseline levels of the biomarkers. Based on 8702 person‐years of follow‐up and 96 stroke/systemic embolic events, the ABC stroke score at 2 months achieved a similar C index of 0.70 (95% CI, 0.65–0.76) as compared with 0.70 (95% CI, 0.65–0.75) at baseline. The ABC stroke score remained well calibrated using predefined risk classes. Conclusions In patients with stable atrial fibrillation, the variability of the cardiac biomarkers and the biomarker‐based ABC stroke score during 2 months are small. The prognostic information by the ABC stroke score remains consistent and well calibrated with similar good predictive performance if patients are retested after 2 months. Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT 00412984.