Sauna for coronary artery disease (chronic ischemic heart disease)
Evidence review
Overview
In the KIHD cohort, more frequent Finnish sauna use was associated with lower risk of sudden cardiac death, fatal coronary heart disease and cardiovascular mortality in a dose-dependent way, and in a Japanese cohort of 30,076 adults almost daily hot-tub bathing was associated with lower incident coronary heart disease; these are associations in general populations, not trials in patients with CAD, and in the KIHD analysis that included women the association was not significant in women alone. In adults with stable CAD, single sauna and warm-footbath sessions acutely improved brachial flow-mediated dilation and coronary flow reserve, but an 8-week randomized trial (4 sessions/week) found no improvement in endothelial function, arterial stiffness or blood pressure. A small non-randomized Japanese study reported improved myocardial perfusion with Waon therapy in chronic total coronary occlusion, and an older German randomized rehabilitation study after bypass surgery found similar LVEF gains with sauna or walking. Older Japanese studies from one group measured invasive hemodynamics during a single 5-minute 107.6 F (42 C) hot-water bath after myocardial infarction: pulmonary arterial and wedge pressures rose during the bath, most in patients with extensive anterior infarction and lower ejection fraction, and both cardiac events that occurred during bathing in a 70-patient series were in patients with lower cardiac function.
Key findings
- KIHD (n=2,315 men, 20.7-year follow-up): sudden cardiac death HR 0.37 (95% CI 0.18-0.75) for 4-7 vs 1 sauna session/week; P for trend .005 for SCD, with similar trends for fatal CHD and CVD.
- KIHD men and women (n=1,688): CVD mortality HR 0.23 (95% CI 0.08-0.65) for 4-7 vs 1 session/week after adjustment, based on 8 deaths in the 4-7 group; not significant in women analysed separately.
- Japanese cohort (n=30,076, no CVD at baseline): almost daily tub bathing vs 0-2 times/week, incident CHD HR 0.65 (95% CI 0.45-0.94); no association with sudden cardiac death.
- RCT in stable CAD (n=41, 8 weeks, 4 sessions/week at 174 F): no difference in FMD, pulse wave velocity, or BP vs control.
- Acute study in stable CAD (n=22): FMD +1.21% (95% CI 0.16-2.26) after one session; SBP fell 19 mmHg.
- Single warm footbath in mild-to-moderate CAD (n=21): coronary flow reserve 1.6 to 2.2 (P<0.001), BP and heart rate unchanged.
- Non-randomized Waon study in chronic total occlusion (n=24): summed stress score improved 16 to 9 (p<0.01) vs no change in controls.
- After bypass surgery (n=43, sauna vs walking rehabilitation): resting LVEF rose about 7-8% in both groups; BP unchanged.
- Single 107.6 F, 5-min bath after myocardial infarction (n=54): wedge pressure rose >10 mmHg in patients with lower LVEF (39.8% vs 56.2%, p<0.01) and more extensive anterior infarction (Matsuzaki 1991); in a 70-patient series both in-bath cardiac events were in the lower-function group (Sorimachi 1999).
Every study we reviewed
6 mixed results · 1 found no effect · 7 found benefit
Each study was checked on PubMed. The colored edge shows the direction of the result. The research library lists 31 studies on coronary artery disease, across all heat and cold therapies, including case reports and older work not graded here.
Non-acute effects of passive heating interventions on cardiometabolic risk and vascular health: systematic review and meta-analysis of randomized controlled trials.
Hamaya R et al. Am J Prev Cardiol. 2025. PubMed 41049507 · DOI · Free full text
- Who
- 20 RCTs of passive heating >=1 week in adults; subgroup with coronary risk or CVD
- What
- Passive heating interventions (hot water bathing, sauna, hot yoga, local heating)
- Protocol
- 2-15
- Measured
- Vascular and cardiometabolic markers
- Result
- No significant pooled effect on FMD (-0.055%, 95% CI -1.11 to 1.00; 3 RCTs), pulse wave velocity (-0.39 m/s, 95% CI -1.01 to 0.22; 3 RCTs), resting heart rate or lipids; CRP was reported by only 2 studies and summarized narratively (no reduction). SBP -2.52 mmHg (95% CI -4.26 to -0.79) in the coronary risk/CVD subgroup, which contained 12 of the 15 SBP trials (between-subgroup heterogeneity p=0.058).
- Limitations
- Heterogeneous modalities and populations; vascular outcomes from only 3 small RCTs each; subgroup analysis; most trials at moderate to high risk of bias; adverse events not pooled.
Finnish sauna bathing and vascular health of adults with coronary artery disease: a randomized controlled trial.
Debray A et al. J Appl Physiol (1985). 2023. PubMed 37650138 · DOI
- Who
- Adults with stable CAD (mean age 62; 33 men, 8 women)
- What
- Unsupervised Finnish sauna vs lifestyle-maintenance control, 8 weeks
- Protocol
- 174 °F · 20-30 min · 4/wk · 8 wk
- Measured
- Brachial FMD, carotid-femoral PWV, reactive hyperemia, BP
- Result
- FMD change: control 0.07% vs sauna 0.15% (interaction P=0.909); no between-group difference in PWV (P=0.816), SBP (P=0.951) or DBP (P=0.292). Heat acclimation occurred (resting core temperature -0.27 C).
- Limitations
- Small; surrogate endpoints only; 8 weeks; not powered for clinical events.
[Use of walking and sauna therapy in the rehabilitation of hypertensive patients with ischemic heart disease following aortocoronary venous bypass operation with special reference to hemodynamics].
Winterfeld HJ et al. Z Kardiol. 1988. PubMed 3260059
- Who
- Untrained hypertensive men with ischemic heart disease after coronary artery bypass grafting (East Germany)
- What
- Rehabilitation with Finnish sauna vs walking/running training
- Measured
- Resting LVEF, peripheral microcirculation (xenon-133 muscle clearance), BP at rest and on exercise
- Result
- Resting LVEF rose by about 7-8% on average in both groups; peripheral microcirculation improved only in the sauna group; blood pressure at rest and during exercise was not influenced.
- Limitations
- German-language report, abstract only; no untreated control, so the LVEF rise cannot be attributed to sauna; randomization details and numeric results limited.
Association between sauna bathing and fatal cardiovascular and all-cause mortality events.
Laukkanen T et al. JAMA Intern Med. 2015. PubMed 25705824 · DOI
- Who
- Middle-aged Finnish men (42-60 y), population-based (KIHD)
- What
- Self-reported Finnish sauna frequency and duration
- Protocol
- <11, 11-19, >19 min · 1 vs 2-3 vs 4-7/wk
- Measured
- Sudden cardiac death, fatal CHD, fatal CVD, all-cause mortality
- Result
- SCD HR 0.78 (95% CI 0.57-1.07) for 2-3 and 0.37 (0.18-0.75) for 4-7 vs 1 session/week (P trend .005); similar trends for fatal CHD, fatal CVD and all-cause mortality (P trend <=.005). Sessions >19 min vs <11 min: SCD HR 0.48 (0.31-0.75).
- Limitations
- Observational; men only; single baseline exposure assessment; not restricted to CAD patients; HRs for fatal CHD/CVD not given in the abstract.
Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women: a prospective cohort study.
Laukkanen T et al. BMC Med. 2018. PubMed 30486813 · DOI · Free full text
- Who
- Finnish men and women aged 53-74 (51% women) (KIHD)
- What
- Self-reported sauna frequency and duration
- Protocol
- about 169 (mean 75.9 C) °F · 13 (median) min · 1 vs 2-3 vs 4-7/wk
- Measured
- Fatal CVD
- Result
- Fully adjusted HR 0.75 (95% CI 0.52-1.08) for 2-3 and 0.23 (0.08-0.65) for 4-7 vs 1 session/week (8 CVD deaths among 205 people in the 4-7 group); sauna frequency improved CVD-mortality risk prediction (C-index +0.0091, P=0.010). No statistically significant association in women analysed separately (low event rates; P for interaction by sex 0.524).
- Limitations
- Observational; wide CI for highest-frequency group (8 deaths); not significant in women alone; general population, not patients with CAD.
Joint associations of sauna bathing and cardiorespiratory fitness on cardiovascular and all-cause mortality risk: a long-term prospective cohort study.
Kunutsor SK et al. Ann Med. 2018. PubMed 28972808 · DOI · Free full text
- Who
- Finnish men (KIHD) with measured cardiorespiratory fitness
- What
- Sauna frequency high (3-7/week) vs low (<=2/week), combined with fitness
- Protocol
- <=2 vs 3-7/wk
- Measured
- CVD and all-cause mortality
- Result
- High vs low sauna frequency: CVD mortality HR 0.74 (95% CI 0.59-0.94); all-cause HR 0.84 (0.72-0.97). High fitness + high sauna vs low/low: CVD mortality HR 0.42 (0.28-0.62).
- Limitations
- Observational; men only; general population.
Habitual tub bathing and risks of incident coronary heart disease and stroke.
Ukai T et al. Heart. 2020. PubMed 32209614 · DOI
- Who
- Japanese adults aged 40-59 without CVD or cancer at baseline (JPHC Study), followed 1990-2009
- What
- Habitual hot-water tub bathing: almost daily vs 0-2 times/week (self-reported)
- Protocol
- 0-2 vs 3-4 vs almost daily/wk
- Measured
- Incident coronary heart disease and stroke
- Result
- Almost daily vs 0-2 times/week: total CVD HR 0.72 (95% CI 0.62-0.84); CHD HR 0.65 (0.45-0.94, P trend 0.065); total stroke HR 0.74 (0.62-0.87); cerebral infarction HR 0.77 (0.62-0.97); intracerebral haemorrhage HR 0.54 (0.40-0.73). No association with sudden cardiac death or subarachnoid haemorrhage.
- Limitations
- Observational association; single baseline questionnaire; residual confounding possible; tub bathing, not sauna; general population without prior CVD.
Acute Vascular Benefits of Finnish Sauna Bathing in Patients With Stable Coronary Artery Disease.
Gravel H et al. Can J Cardiol. 2021. PubMed 32615263 · DOI
- Who
- Adults with stable CAD (mean age 67; 20 men)
- What
- Single Finnish sauna session (2 x 10 min separated by 10 min rest)
- Protocol
- 182 °F · 20 (2 x 10) min · single session/wk
- Measured
- Brachial FMD about 51 min after sauna
- Result
- FMD +1.21% (95% CI 0.16-2.26, P=0.04); SBP -19 mmHg (95% CI -31 to -6); DBP -6 mmHg; reactive hyperemia unchanged.
- Limitations
- Acute, single-arm, no control condition; acute FMD change did not translate into chronic benefit in the later RCT.
Repeated sauna therapy improves myocardial perfusion in patients with chronically occluded coronary artery-related ischemia.
Sobajima M et al. Int J Cardiol. 2013. PubMed 22244482 · DOI
- Who
- Patients with myocardial ischemia related to chronic total coronary occlusion
- What
- Daily Waon therapy (n=16) vs no therapy (n=8), 3 weeks
- Protocol
- 140 °F · 15 min · daily/wk · 3 wk
- Measured
- Thallium-201 adenosine perfusion (summed stress and difference scores), treadmill time, FMD
- Result
- Waon: SSS 16 to 9 and SDS 7 to 3 (both p<0.01); treadmill time 430 to 511 s (p<0.01); FMD 4.1% to 5.9% (p<0.05). No change in controls.
- Limitations
- Small; allocation not described as randomized; open-label; single center.
A warm footbath improves coronary flow reserve in patients with mild-to-moderate coronary artery disease.
Yoon SJ et al. Echocardiography. 2011. PubMed 21854441 · DOI
- Who
- Patients with mild-to-moderate coronary artery disease, mean age 61, 33% men (Korea)
- What
- Single warm footbath
- Protocol
- single session/wk
- Measured
- Coronary flow reserve (adenosine, LAD Doppler), BP, heart rate
- Result
- Coronary flow reserve 1.6 to 2.2 (P<0.001); diastolic mean flow velocity 18.3 to 21.5 cm/s (P=0.002); BP and heart rate unchanged; no adverse effects.
- Limitations
- Acute; uncontrolled; small; footbath rather than sauna.
Acute effects of Finnish sauna and cold-water immersion on haemodynamic variables and autonomic nervous system activity in patients with heart failure.
Radtke T et al. Eur J Prev Cardiol. 2016. PubMed 26152773 · DOI
- Who
- Men with chronic heart failure (n=12, mean age 62), coronary artery disease (n=13) and controls (n=12) (Switzerland)
- What
- Two consecutive Finnish sauna exposures at 176 F followed by head-out cold-water immersion at 54 F (single session)
- Protocol
- 176 (sauna); 54 (cold immersion) °F · single session/wk
- Measured
- Cardiac output, blood pressure, heart rate variability, arrhythmias
- Result
- In the 13 CAD patients, cardiac output did not rise after sauna (it rose in the heart failure and control groups); LF/HF ratio stayed elevated after the first sauna in CAD patients and controls; systolic BP fell during sauna and rose with cold-water immersion in all groups (p<0.05). Sauna and cold immersion were well tolerated.
- Limitations
- Single session; small; stable selected men; acute tolerability only, not efficacy.
Comparisons between hemodynamics, during and after bathing, and prognosis in patients with myocardial infarction.
Sorimachi M et al. Jpn Circ J. 1999. PubMed 10462019 · DOI
- Who
- Patients with myocardial infarction (Showa University, Japan)
- What
- Single supine hot-water bath in a Hubbard tank, 107.6 F (42 C) tap water for 5 min, with hemodynamic monitoring; patients then followed for cardiac events
- Protocol
- 107.6 °F · 5 min
- Measured
- Pulmonary capillary wedge pressure 10 min after bathing; cardiac events over a mean 37-month follow-up
- Result
- Patients whose wedge pressure did not fall after the bath (group A) had lower LVEF (39.7% vs 53.6%, p<0.01) and work capacity (4.5 vs 5.6 METs, p<0.05) than those whose pressure fell (group B); cardiac events during follow-up: 6 in group A vs 3 in group B; both cardiac events that occurred during bathing were in group A.
- Limitations
- Single bath; no non-bathing comparison; group sizes and time since infarction not given in the abstract; same research group as the 1988 and 1991 studies, so patients may overlap.
[Blood flow changes on bathing in patients with myocardial infarction: studies by Doppler echocardiography].
Matsuzaki A et al. J Cardiol. 1991. PubMed 1843503
- Who
- Patients with myocardial infarction, mean age 56 (19 extensive anterior, 13 anterior, 17 inferior, 5 anterior and inferior) (Japan)
- What
- Single supine hot-water bath in a Hubbard tank, 107.6 F (42 C) tap water for 5 min, with Swan-Ganz catheter and Doppler echocardiography
- Protocol
- 107.6 °F · 5 min
- Measured
- Rise in pulmonary capillary wedge pressure during the bath; Doppler flow indices
- Result
- Patients whose wedge pressure rose more than 10 mmHg during the bath more often had extensive anterior infarction (p<0.05), lower LVEF (39.8% vs 56.2%, p<0.01), higher LV end-diastolic pressure (17.8 vs 14.8 mmHg, p<0.05) and shorter exercise time (6.3 vs 10.2 min, p<0.001); in this group pulmonary arterial and right atrial pressures rose markedly during bathing and LV outflow velocity fell.
- Limitations
- Single bath; physiological outcomes only; article in Japanese and abstract truncated; same research group as the 1988 and 1999 studies.
[Effects of bathing on cardiac function in patients with myocardial infarction: hemodynamic and Doppler echocardiographic studies].
Ozawa M et al. J Cardiol. 1988. PubMed 3267735
- Who
- Patients with myocardial infarction, mean age 55.6 (11 anterior or anteroseptal) (Japan)
- What
- Single supine hot-water bath in a Hubbard tank, 107.6 F (42 C) tap water for 5 min, with Swan-Ganz catheter and Doppler echocardiography
- Protocol
- 107.6 °F · 5 min
- Measured
- Hemodynamics during and after bathing
- Result
- Blood pressure, pulmonary arterial pressure, wedge pressure, right atrial pressure, heart rate and cardiac index rose significantly during the bath and systemic and pulmonary vascular resistance fell; after the bath the pressures fell and stayed below baseline.
- Limitations
- Single bath; 14 patients; physiological outcomes only; article in Japanese, abstract truncated.
Protocols used in the studies
Cohorts: habitual Finnish sauna, strongest associations at 4-7 sessions/week and sessions >19 min. RCT in stable CAD: 174 F (79 C), 20-30 min, 4 sessions/week for 8 weeks, unsupervised. Acute study: 182 F (81 C), 2 x 10 min. Waon: 140 F (60 C) far-infrared sauna 15 min plus 30 min blanket rest, daily for 3 weeks. Japanese cohort: household hot-tub bathing (temperature not reported). Footbath study: a single warm footbath (temperature not given in abstract). Acute tolerability study: two 176 F (80 C) Finnish sauna exposures followed by 54 F (12 C) cold immersion. Post-infarction hemodynamic studies: a single supine 107.6 F (42 C) tap-water bath for 5 minutes in a Hubbard tank with catheter monitoring.
What is still unknown
No RCT with clinical endpoints in CAD; whether cohort associations are causal or reflect healthier users is unresolved; whether acute vascular improvements persist with repeated use; safety and benefit in women, older adults and after recent coronary events; optimal protocol for patients with established CAD. Whether hot-water immersion and dry sauna differ in safety after myocardial infarction with reduced ejection fraction.
Safety
Cautions for sauna in this condition
- A single sauna session lowered SBP by 19 mmHg and raised heart rate by 27 beats/min in stable CAD (PMID 32615263); patients on nitrates or other vasodilators may be prone to hypotension on standing.
- In stable CAD, cardiac output did not rise after a 176 F Finnish sauna and sympathetic heart-rate-variability indices stayed elevated after the first exposure; cold immersion after sauna raised systolic BP (PMID 26152773).
- Trials enrolled stable CAD only; no trial data support sauna use in unstable angina or soon after an acute coronary event.
- Alcohol intoxication is a recurrent feature of sauna deaths (about half of Finnish cases, PMID 18471223; 76 of 103 Korean cases with BAC >=0.08%, PMID 29926439).
- After myocardial infarction, a 5-minute 107.6 F (42 C) bath raised pulmonary arterial, wedge and right atrial pressures; wedge pressure rose by more than 10 mmHg in patients with extensive anterior infarction and lower LVEF (PMIDs 3267735, 1843503), and both cardiac events during bathing in a 70-patient series occurred in patients with lower cardiac function (PMID 10462019). Hot-water immersion loads the heart differently from dry sauna.
For clinicians
Suggested rationale
Frequent sauna use is associated with lower sudden cardiac and cardiovascular mortality in a long-term prospective cohort (Laukkanen 2015, SCD HR 0.37 for 4-7 vs 1 session/week), and frequent tub bathing with lower incident CHD in a Japanese cohort (Ukai 2020), but an RCT in stable CAD found no improvement in vascular function (Debray 2023); evidence is associational and sauna would be adjunctive to secondary prevention.
Suggested wording only. The treating clinician decides whether it reflects their clinical judgment for this patient.
Typical ICD-10 codes: I25.10, I25.2, I20.9. Examples only; the clinician assigns the code.
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