Heart Failure in Women: Why It Looks Different, Starts Later, and Gets Missed Longer

When most people think of heart failure, they imagine a particular picture: an older man, a weakened heart that cannot pump adequately, dramatic breathlessness, a dilated heart on echocardiogram with an ejection fraction of 30 percent. This picture is accurate for the predominant form of heart failure in men — heart failure with reduced ejection fraction, or HFrEF. It is largely inaccurate for the predominant form of heart failure in women.

In women, the most common form of heart failure is HFpEF: heart failure with preserved ejection fraction. The heart contracts normally — ejection fraction is above 50 percent — but it is stiff. It does not relax adequately between beats. It cannot fill at low pressures. When demand increases, whether from exertion, eating, or lying flat, the pressures required to fill the stiff ventricle back up into the lungs, producing breathlessness, fluid retention, and functional limitation.

HFpEF now accounts for more than half of all heart failure hospitalizations in women over 65. It is less well understood than HFrEF, has fewer evidence-based treatments, and carries outcomes in women that are worse than most women who receive the diagnosis are told. It is also frequently diagnosed late — because the symptoms develop gradually, because the ejection fraction is “normal,” and because the typical patient presentation (older, postmenopausal, hypertensive, obese, without prior MI) does not match the cultural script for heart disease in women.

What Heart Failure Is — and the Two Distinct Forms

Heart failure is not a single disease. It is a clinical syndrome in which the heart cannot provide adequate cardiac output to meet the body’s metabolic demands, or can only do so at abnormally elevated filling pressures. The consequences are symptoms: breathlessness from elevated pulmonary venous pressures, fatigue from reduced perfusion to working muscles, and fluid retention from compensatory neurohormonal activation (RAAS and sympathetic nervous system) that tries to maintain blood pressure and perfusion at the cost of volume overload.

HFrEF — heart failure with reduced ejection fraction, EF below 40% — occurs when the heart muscle contracts weakly. The causes include prior myocardial infarction (scar tissue cannot contract), viral myocarditis, dilated cardiomyopathy from toxins or genetic causes, and severe valvular disease. HFrEF is more common in men because men have higher rates of MI and obstructive coronary artery disease at earlier ages.

HFpEF — heart failure with preserved ejection fraction, EF above 50% — occurs when the heart contracts normally but relaxes abnormally. The ventricle is stiff and non-compliant. It fills adequately at rest but cannot increase its filling rate with exertion. Filling pressures rise with activity, back-pressure into the lungs causes breathlessness, and the clinical picture of heart failure develops without the weak, dilated heart of HFrEF.

HFpEF accounts for approximately 50 to 65 percent of all heart failure cases, and women represent 55 to 70 percent of HFpEF patients in most published series. It is, in the most literal sense, predominantly a women’s disease — and one that is systematically less studied, less understood, and less treatable than the male-predominant form.

Why Women Develop HFpEF: The Biological Drivers

The sex difference in heart failure phenotype is not random. It reflects fundamental differences in how the female heart responds to the same risk factors that affect the male heart.

Hypertension and the female myocardial response. When a heart faces chronic pressure overload from hypertension, it hypertrophies — the myocardium thickens in response to the increased wall stress. In men, this hypertrophy tends to be eccentric: the chamber dilates as well as thickens, accommodating volume load. In women, hypertrophy tends to be concentric: the wall thickens without equivalent chamber dilation, producing a smaller, thicker, stiffer ventricle. This concentric remodeling pattern is more strongly associated with diastolic dysfunction and HFpEF.

The same blood pressure elevation in a man and a woman produces different cardiac structural responses — and the female response is more strongly associated with the eventual HFpEF phenotype.

Myocardial fibrosis. Diastolic stiffness is driven in large part by fibrosis — the deposition of collagen in the myocardial interstitium. Collagen cross-linking, mediated by enzymes including lysyl oxidase, makes existing collagen stiffer. Women have higher rates of myocardial fibrosis per unit of pressure exposure and per decade of hypertension than men, based on cardiac MRI T1 mapping studies. The mechanisms include sex differences in aldosterone signaling (aldosterone promotes myocardial fibrosis) and in transforming growth factor-beta (TGF-beta) activity in the female heart.

Estrogen withdrawal at menopause. Estrogen has direct effects on the cardiomyocyte — it promotes mitochondrial function, reduces inflammatory signaling in the heart muscle, and influences the calcium-handling proteins that govern myocardial relaxation. When estrogen declines at menopause, these cardioprotective effects are removed at precisely the same time that blood pressure typically rises, visceral fat accumulates, and metabolic dysfunction (insulin resistance, glucose intolerance) increases. The convergence of adverse metabolic and inflammatory changes with the loss of direct myocardial hormonal support creates the highest-risk window for HFpEF onset in women.

The prevalence of HFpEF rises steeply in women between ages 55 and 70 — the postmenopausal decade — in a pattern that does not have an equivalent in men of the same age.

Obesity and adipose inflammation. Obesity is among the strongest risk factors for HFpEF, and in women, postmenopausal weight gain — driven by the metabolic shift at menopause — compounds the myocardial effects of hypertension. Adipose tissue, particularly the visceral fat that increases at menopause, is metabolically active: it secretes inflammatory cytokines (IL-6, TNF-alpha), promotes insulin resistance, and elevates RAAS activity. All of these pathways drive myocardial fibrosis and diastolic dysfunction. Women with obesity who have hypertension have cumulative HFpEF risk that substantially exceeds the sum of the individual risk factors.

How HFpEF Presents in Women: The Symptoms That Don’t Shout

HFpEF in women frequently develops insidiously. There is rarely a dramatic decompensation event that forces the diagnosis. Instead, there is a gradual decline in functional capacity that is attributed to other things for years before the correct diagnosis is made.

Breathlessness on exertion is the cardinal symptom. A woman who describes becoming short of breath climbing two flights of stairs when previously she could climb four, who has to rest after carrying grocery bags from the parking lot, who feels she cannot get enough air when walking her dog at a moderate pace — these are HFpEF symptoms. They are also the symptoms attributed, frequently, to being out of shape, to gaining weight at menopause, to getting older.

Ankle and leg swelling from fluid retention is common. This too is attributed to standing all day, to the weather, to travel. Pitting edema in a postmenopausal woman with hypertension and breathlessness should prompt HFpEF evaluation.

Orthopnea — breathlessness when lying flat — and paroxysmal nocturnal dyspnea — waking suddenly at night with severe breathlessness — are more specific HFpEF symptoms. A woman who has started sleeping with two or three pillows to avoid breathlessness when lying flat has a symptom that should trigger immediate cardiac evaluation.

Fatigue disproportionate to activity is particularly common in women with HFpEF. The reduced cardiac output reserve — the inability to increase cardiac output adequately with exertion — produces a functional fatigue that is physiologically real and often mischaracterized as fibromyalgia, depression, menopause-related fatigue, or deconditioning.

Diagnosis: Why a Normal Ejection Fraction Is Not Reassurance

The most common misinterpretation in HFpEF diagnosis occurs at the echocardiogram report. A woman’s echo shows an ejection fraction of 60 percent — “normal” — and she is told her heart is fine. The EF, however, is only one measurement. HFpEF requires a systematic assessment of diastolic function, not just the ejection fraction.

The diagnostic criteria for diastolic dysfunction on echocardiogram include:

• E/e’ ratio (the ratio of mitral inflow velocity to mitral annular velocity) — a ratio above 14 suggests elevated filling pressures
• Tricuspid regurgitation velocity — elevated values estimate pulmonary artery pressures and indirectly reflect elevated left-sided filling pressures
• Left atrial volume index — a dilated left atrium in the setting of a stiff left ventricle suggests chronically elevated filling pressures
• Septal e’ velocity — reduced tissue Doppler velocity at the mitral annulus indicates impaired myocardial relaxation

A normal ejection fraction with multiple abnormal diastolic parameters on echo, in the setting of clinical symptoms of heart failure, supports the HFpEF diagnosis. When the resting echo is equivocal and symptoms are clearly exertional, diastolic stress testing — exercise echo or exercise hemodynamic catheterization — can provoke the filling pressure elevation that confirms HFpEF.

BNP and NT-proBNP — biomarkers of ventricular wall stress — are elevated in most women with HFpEF but at lower absolute values than in HFrEF. The sex-specific cutoffs for BNP interpretation in HFpEF are an area of ongoing refinement; lower BNP values in women should not be interpreted as excluding HFpEF when clinical suspicion is present.

Treatment: The Most Difficult Therapeutic Challenge in Cardiology

For HFrEF, the therapeutic framework is well-established: ACE inhibitors or ARBs or ARNI (sacubitril/valsartan), beta-blockers, mineralocorticoid receptor antagonists, and SGLT2 inhibitors (dapagliflozin, empagliflozin) have each shown mortality benefit in randomized trials. Women with HFrEF receive these medications; the benefits are established.

For HFpEF, the therapeutic landscape was until recently almost empty of proven mortality-reducing treatments. The condition was documented, risk factors identified, symptoms managed with diuretics, and patients advised regarding blood pressure and weight control — without a disease-modifying intervention.

The EMPEROR-Preserved trial (empagliflozin, an SGLT2 inhibitor) changed this. Published in the New England Journal of Medicine in 2021, EMPEROR-Preserved enrolled over 5,000 patients with HFpEF and showed that empagliflozin reduced the primary endpoint of cardiovascular death or heart failure hospitalization by 21 percent. Women made up approximately 45 percent of the trial population. The benefit was consistent across subgroups.

Beyond SGLT2 inhibitors, blood pressure control remains the most important disease-modifying intervention — because hypertension is the primary driver of HFpEF in women, and because each increment of blood pressure reduction slows the progression of diastolic dysfunction and myocardial fibrosis. ACE inhibitors, ARBs, and spironolactone are commonly used in HFpEF for blood pressure control and for their anti-fibrotic effects, though their mortality benefit in HFpEF specifically has been less conclusive than in HFrEF.

Loop diuretics (furosemide, bumetanide) manage fluid overload and reduce symptoms, but they do not modify the underlying disease. They are necessary for quality of life management; they are not curative.

Supervised aerobic exercise training — cardiac rehabilitation — improves functional capacity and quality of life in women with HFpEF, even when pharmacological options are limited. The mechanism includes improved peripheral vascular function and skeletal muscle oxygen extraction, which reduce the cardiac output demands at any given workload. Women with HFpEF who participate in structured cardiac rehabilitation programs have documented improvements in six-minute walk distance, peak VO2, and quality of life scores.

Atrial Fibrillation and HFpEF: A Dangerous Pairing in Women

Atrial fibrillation and HFpEF co-occur at high rates and reinforce each other through shared pathophysiology. The same drivers that produce diastolic dysfunction — hypertension causing left atrial pressure elevation, left atrial dilation, and fibrosis — create the atrial substrate for AF. In women with HFpEF, AF is present in approximately 40 to 65 percent of patients in large registry series, and its presence worsens outcomes substantially beyond what either condition carries independently.

The interaction between AF and HFpEF in women has specific hemodynamic consequences. In HFpEF, the stiff left ventricle depends more than normal on atrial contraction to complete ventricular filling during late diastole. The loss of organized atrial contraction with AF — and the loss of the “atrial kick” that contributes 20 to 30 percent of ventricular filling in healthy individuals but a higher proportion in stiff ventricles — can precipitate acute symptomatic decompensation in a woman whose resting hemodynamics were marginally compensated. An HFpEF patient who goes into AF may have a dramatic increase in symptoms that appears acute but reflects a chronic diastolic vulnerability being unmasked.

Rate control in AF with HFpEF requires careful consideration: the stiff ventricle requires adequate diastolic filling time, which means very rapid ventricular rates are especially harmful. However, overly aggressive rate slowing can reduce cardiac output in a heart that also has limited stroke volume augmentation. Beta-blockers and calcium channel blockers are commonly used for rate control, with beta-blockers preferred when concomitant hypertension or reduced EF component is present.

Rhythm control — restoring and maintaining sinus rhythm — has appeal in HFpEF because restoring the atrial kick may improve hemodynamics beyond what rate control achieves. The EAST-AFNET 4 trial showed cardiovascular benefit for early rhythm control in AF broadly; whether women with HFpEF specifically derive disproportionate benefit from rhythm control is an active area of clinical investigation.

Women with HFpEF who also have AF should have both conditions managed explicitly rather than treating each in isolation. The cardiovascular prognosis of the combined presentation depends heavily on whether both the rhythm disorder and the diastolic dysfunction are addressed in a coordinated management plan.

What to Do This Week

If you have breathlessness with activities that previously felt comfortable, ankle swelling that is new or worsening, or if you find yourself needing extra pillows to sleep comfortably, these symptoms warrant prompt cardiac evaluation — not a “let’s watch and wait” approach.

If you have been told your echocardiogram was normal and specifically told your ejection fraction is normal, ask whether diastolic function was assessed. Ask what your E/e’ ratio was. Ask whether your left atrium size was measured. Normal ejection fraction in the presence of abnormal diastolic parameters is the HFpEF picture — and requires different management than a truly normal cardiac evaluation.

If you have hypertension that has been inadequately controlled — systolic consistently above 130 mmHg in the postmenopausal years — understand that each year of elevated pressure is a year of accelerating diastolic dysfunction in the female myocardium. Blood pressure management is HFpEF prevention, not a separate issue.