What happens to the heart during the transition

Three decades of cohort and trial data, led by the Study of Women's Health Across the Nation (SWAN), show one consistent pattern: cardiovascular risk factors and arterial structure change fastest in late perimenopause and the year around the final menstrual period.

Abstract ribbon of translucent tissue glowing orange to pink, evoking an artery wall.

Lipids rise sharply around the final period

Lipids rise fastest in the year around the final menstrual period

SWAN, n = 1,054 women. Annual slope by interval relative to the final menstrual period (FMP); error bars = 95% CI.

  • More than 12 months before FMP
  • Within 12 months of FMP
  • More than 12 months after FMP
Annual change, mg/dL per year (95% CI)
MeasureMore than 12 months before FMPWithin 12 months of FMPMore than 12 months after FMP
Total cholesterol2.98 [2.25, 3.71]6.47 [5.25, 7.69]−0.16 [−0.87, 0.55]
LDL cholesterol1.57 [0.94, 2.20]5.20 [4.12, 6.28]0.14 [−0.49, 0.77]
Apolipoprotein B0.67 [0.12, 1.22]3.24 [2.36, 4.12]−0.40 [−0.89, 0.09]

Source: Matthews KA et al. J Am Coll Cardiol. 2009;54(25):2366-2373.Reference 1

In 1,054 women followed through the transition, LDL cholesterol rose more than 3 times faster in the 12 months around the final menstrual period than in the years before it. The investigators attributed this rise to the transition itself, beyond chronological aging.

Arteries remodel in late perimenopause

A hand holding a stethoscope to the chest over a soft pink knit sweater.

Carotid wall thickness and arterial diameter grow fastest in late perimenopause, significantly faster than before the transition. Women whose estradiol stayed higher before menopause had lower odds of carotid plaque afterward. Investigators have described late perimenopause as a period of vascular remodeling where early intervention may yield the greatest benefit.

Reference 2 · Reference 3

Symptoms of the transition track vascular risk

Markers of the transition carry 1.5 to 1.9 times the cardiovascular risk

Point estimate and 95% CI from adjusted models; values above 1 indicate higher risk. Log scale.

Hazard or odds ratio and 95% CI
MeasureEstimate [95% CI]
Persistent frequent hot flashes: CV events, HR, SWAN, n = 3,083, up to 22 y (Thurston, JAHA 2021)1.77 [1.33, 2.35]
Frequent hot flashes at baseline: CV events, HR, SWAN, n = 3,083 (Thurston, JAHA 2021)1.51 [1.05, 2.17]
Hot flashes: aortic calcification, OR, SWAN Heart, n = 492 (Thurston, Circulation 2008)1.63 [1.07, 2.49]
Perimenopause vs premenopause: poor CV health (LE8), aOR, NHANES, n = 9,248 (Nayak, JAHA 2026)1.92 [1.13, 3.26]
Perimenopause vs premenopause: poor lipid score, aOR, NHANES, n = 9,248 (Nayak, JAHA 2026)1.76 [1.12, 2.76]
Perimenopause vs premenopause: poor glucose score, aOR, NHANES, n = 9,248 (Nayak, JAHA 2026)1.83 [1.06, 3.17]

Sources: Thurston RC et al. JAHA 2021;10:e017416 and Circulation 2008;118:1234-40; Nayak A et al. JAHA 2026;15:e046898.Ref. 4 · Ref. 6 · Ref. 7

Women with hot flashes show lower endothelial function, more aortic calcification and thicker carotid walls, and these links hold after adjusting for estradiol. Over up to 22 years, persistent frequent hot flashes predicted a 77% higher risk of cardiovascular events.

Timing changes the effect of treatment

Timing matters: therapy started early shows no harm or lower risk

Hazard ratio and 95% CI for cardiovascular disease, hormone therapy vs none, in women with hot flashes.

  • Started early
  • Started later
Hazard ratio and 95% CI
MeasureEstimate [95% CI]
WHI, estrogen alone, Age 50 to 59 at start0.85 [0.53, 1.35]
WHI, estrogen alone, Age 60 to 69 at start1.31 [0.90, 1.90]
WHI, estrogen alone, Age 70 to 79 at start1.95 [1.06, 3.59]
WHI, estrogen plus progestin, Age 50 to 59 at start0.84 [0.44, 1.57]
WHI, estrogen plus progestin, Age 60 to 69 at start0.84 [0.51, 1.39]
WHI, estrogen plus progestin, Age 70 to 79 at start3.22 [1.36, 7.63]
SWAN target trial emulation, Started within 10 years of menopause0.73 [0.58, 0.93]
SWAN target trial emulation, Started more than 10 years after menopause1.53 [0.66, 3.52]

Sources: Rossouw JE et al. JAMA Intern Med 2025;185(11):1330-39 (WHI, ASCVD); Wang Z et al. JAMA Intern Med 2026. Not a recommendation for prevention.Ref. 8 · Ref. 9

In women with hot flashes, hormone therapy started at age 50 to 59 or within 10 years of menopause showed no increase, or a reduction, in cardiovascular events, while therapy started at 70 or older raised risk.

The investigators do not recommend hormone therapy for cardiovascular prevention. Their shared conclusion is that randomized trials in perimenopausal women are still missing.