Sweat Your Heart? Sauna for CHF
Sweat Your Heart? Sauna for CHF
Abstract & Commentary
By Russell H. Greenfield, MD, Editor
Synopsis: The prevalence of chronic heart failure has steadily increased with improvements in survival rates for cardiac patients; however, heart failure remains a disorder whose typically progressive course worsens quality of life, and thus far has defied most conventional medical approaches. New ideas leading to new treatments are needed. The researchers behind this small intervention trial examined the effect of repeated sauna therapy on exercise tolerance in people with congestive heart failure and found significant benefits.
Source: Ohori T, et al. Effect of repeated sauna treatment on exercise tolerance and endothelial function in patients with chronic heart failure. Am J Cardiol 2012;109:100-104.
The researchers behind this clinical intervention trial sought to assess the impact of Waon therapy (repeated sauna therapy) on exercise tolerance in people with congestive heart failure (CHF). Subjects had to have stable, compensated NYHA functional class II heart failure and/or previous hospitalization for worsening failure to be included in the trial; a total of 41 subjects entered into the protocol (mean age 68 years). Participants underwent Waon therapy with a far-infrared dry sauna (temperature maintained at 60° C) daily on weekdays for 3 weeks (n = 15 sessions) while continuing to receive conventional medical care for CHF. Treatment consisted of the subjects initially sitting in the sauna for 15 minutes, followed by bed rest for 30 minutes while covered with a blanket to maintain warmth. Assessments completed before and after the 3 weeks of intervention included body weight, 6-minute walk distance (6MWD), cardiopulmonary exercise testing in those physically able to pump the pedals of an ergometer (n = 20), and symptom-limited cardiopulmonary exercise testing using expired gas analysis. Vascular endothelial function was evaluated through determination of flow-mediated dilation (FMD) of the brachial artery. Echocardiography was performed, as was measurement of neurohumoral factors and the number of circulating CD34+ cells. Subjects were weighed before and after the therapy and drank water to compensate for the weight loss.
By the end of the 3-week study significant improvements with Waon therapy had been identified, including an increase in left ventricular ejection fraction from 30.4% to 32.5% (P = 0.023), an improvement in peak oxygen uptake, slight improvement in left ventricular ejection fraction, a reduction in plasma norepinephrine levels from 400 to 300 pg/mL (P = 0.015), a decrease in brain natriuretic peptide from 550-416 pg/mL (P = 0.035), improvement in FMD from 3.5%-5.5% (P < 0.001), and an increase in 6MWD from 337-379 m (P < 0.001). There was also an increase in the number of circulating CD34+ cells (P = 0.025). A multivariate analysis revealed that change in FMD was the only independent determinant of change in 6MWD. Findings did not vary according to severity of heart failure or subject age.
The authors concluded that repeated sauna therapy in people with chronic heart failure may improve exercise tolerance in association with improvement in endothelial function.
Commentary
The findings from this small study are startling, though perhaps they shouldn't be, as the researchers reference five prior studies suggesting that significant cardiovascular benefits could be expected from repeated sauna therapy. Compelling, however, are the conclusions that three weeks of Waon therapy in people with CHF not only improves exercise tolerance and ejection fraction, but also curtails neurohumoral activation and enhances endothelial function; this in the setting of a disease whose progression typically is deemed inexorable, in large part due to persistent deterioration in endothelial and cardiac function associated with neurohumoral activation and cardiac remodeling. The theory currently holding sway regarding potential mechanistic actions of Waon therapy and its cardiovascular health benefits is that such treatment may increase nitric oxide bioavailability, thus creating a direct benefit to endothelial function, but not a direct impact on cardiac function.
There is at least one other interesting finding noted by the study authors, that being the effect of Waon therapy on the number of circulating CD34+ cells. These cells are considered to be precursors of endothelial progenitor cells (EPCs), which since being identified in the late 1990s have been used alternately as biomarkers for cardiovascular disease or actual angiogenic therapies that might promote repair of damaged vascular endothelium.1 This therapeutic approach is in its relative infancy, but interest in it has spawned a large number of research studies in recent years.
It is important to keep in mind that the current study has major limitations, not the least of which are the small sample size, the brief duration of treatment, the lack of a control group, and the short follow-up period. Nonetheless, findings such as these have the potential to leave us with a sense of wonder in the face of complex issues such as heart failure could it be that a straightforward, inexpensive treatment that raises core body temperature by 1.0-1.2° C is sufficient to help improve cardiovascular fitness in people with CHF? It is too early to say, but there is ample reason for excitement as we await the findings of future studies on the topic that must surely be forthcoming. Sometimes the simple, elegant approach to problems yields important answers it would be good news for those experiencing CHF, indeed, if such were the case here.
Reference
1. Siddique A, et al. Endothelial progenitor cells: What use for the cardiologist? J Angiogen Res 2010, 2:6. Doi: 10.1186/2040-2384-2-6.
The prevalence of chronic heart failure has steadily increased with improvements in survival rates for cardiac patients; however, heart failure remains a disorder whose typically progressive course worsens quality of life, and thus far has defied most conventional medical approaches. New ideas leading to new treatments are needed. The researchers behind this small intervention trial examined the effect of repeated sauna therapy on exercise tolerance in people with congestive heart failure and found significant benefits.Subscribe Now for Access
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