What Is the Most Common Cause of Death in Heart Failure Patients?

Cardiovascular events account for roughly two-thirds of all deaths in people with heart failure, and the single most common specific cause is progressive heart failure itself, sometimes called pump failure. In a large community-based study, cardiovascular disease caused about 66% of deaths after a heart failure diagnosis, with the remainder attributed to non-cardiovascular conditions like cancer, infection, and kidney disease. But the picture changes substantially depending on the type of heart failure, how sick the patient is, and how old they are.

Why Cardiovascular Death Dominates

Heart failure is, at its core, a condition in which the heart can no longer pump blood effectively enough to meet the body’s needs. So it makes intuitive sense that the heart itself is the organ most likely to give out. A systematic review of deaths after heart failure onset in Olmsted County, Minnesota found that cardiovascular disease was responsible for 66.1% of all deaths, though that figure shifted depending on the type of heart failure: 69.9% of deaths in people whose hearts squeezed weakly (reduced ejection fraction) versus 44.5% in people whose hearts squeezed normally but filled poorly (preserved ejection fraction).¹ Data from the European Society of Cardiology’s long-term heart failure registry tells a broadly similar story: cardiovascular death was the leading category at one year regardless of heart failure subtype, though the proportion varied from about 47% in preserved ejection fraction to about 54% in reduced ejection fraction.²

Within the cardiovascular category, two mechanisms account for most deaths: progressive pump failure and sudden cardiac death. Understanding the balance between these two has been one of the most active areas of heart failure research for decades, because the prevention strategies for each are quite different.

Progressive Pump Failure

Progressive pump failure means the heart gradually loses its ability to circulate blood until organs begin to shut down. Fluid backs up into the lungs, kidneys slow their filtering, and the patient deteriorates over days or weeks despite treatment. In one long-term cohort study that tracked cause of death by underlying heart failure etiology, progressive heart failure was the most common specific cause of death in the overall population, accounting for about 31% of all deaths.³ In another study focused on patients with congestive heart failure, pump failure was even more dominant, responsible for 49% of deaths compared with 33% from sudden death.⁴

The risk factors for dying from pump failure are largely markers of how advanced the disease has become: being in a severe functional class (barely able to walk across a room without symptoms), having a very low ejection fraction, elevated stress hormones, and poor exercise tolerance. These are the patients whose hearts are running on empty, and the final event is often a hospitalization for fluid overload that the medical team cannot reverse.

Sudden Cardiac Death

Sudden cardiac death is the other major cardiovascular killer in heart failure, and it looks very different from pump failure. The patient may have been relatively stable, then develops a lethal heart rhythm, typically a rapid chaotic rhythm called ventricular fibrillation, and dies within minutes unless defibrillation is performed. Sudden cardiac death accounts for a large share of mortality in heart failure with reduced ejection fraction, frequently triggered by ventricular arrhythmias.⁵

The mechanisms that set the stage for these fatal rhythms are layered. Scarring in the heart muscle creates electrical short circuits. Stretched, weakened walls alter the way electrical signals travel. On top of that structural vulnerability, short-term triggers like drops in potassium or magnesium, surges in stress hormones, and medication side effects can push an already unstable heart over the edge.⁶ This is why implantable defibrillators have become standard treatment for many heart failure patients: the device monitors for dangerous rhythms and delivers a shock within seconds, buying time that would otherwise be measured in minutes.

How Disease Severity Shifts the Balance

One of the more counterintuitive findings in this field is that the sickest heart failure patients are actually less likely to die suddenly and more likely to die from pump failure. The Seattle Heart Failure Model, developed from a large dataset of over 2,000 deaths, showed this starkly. Among patients with the mildest disease scores, sudden death outnumbered pump failure death by a ratio of 7 to 1. As disease severity climbed, that ratio flipped, reaching 1 to 2 in the sickest group, meaning pump failure killed twice as many as sudden death.⁷

This pattern has real clinical implications. A patient with mild heart failure and a weak heart may benefit most from a defibrillator, because sudden death is the likeliest threat. A patient who is in and out of the hospital with fluid overload and barely functional may not benefit from a defibrillator at all, because the heart is more likely to simply give out gradually. Getting this distinction right is one of the harder judgment calls in cardiology.

Heart Failure Phenotype Makes a Big Difference

Heart failure is not one disease. Cardiologists divide it into subtypes based on how well the heart squeezes, measured as ejection fraction. These subtypes have meaningfully different death profiles.

In heart failure with reduced ejection fraction (HFrEF), sudden cardiac death is particularly prominent. One study found that about 36% of deaths in HFrEF patients were sudden, compared with just 11% in those with preserved ejection fraction (HFpEF). The cumulative incidence of sudden death at follow-up was 16.7% in HFrEF versus 5.9% in HFpEF.⁸ Patients in the middle category, called mid-range ejection fraction (HFmrEF), fell between the two groups.

The flip side is that non-cardiac deaths are much more common in HFpEF. In that same study, 45% of deaths in HFpEF patients were non-cardiac, compared with 26% in HFrEF.⁸ This makes sense when you consider that HFpEF patients tend to be older and carry a heavier burden of other conditions like diabetes, kidney disease, and obesity. Their heart failure is real and debilitating, but the disease that ultimately kills them may originate somewhere else.⁹

The Underlying Cause of Heart Failure Matters Too

Not all weak hearts got that way for the same reason, and the original cause shapes the mortality pattern. In patients whose heart failure stems from coronary artery disease (ischemic cardiomyopathy), cardiovascular death accounted for about 60% of deaths. In patients with dilated cardiomyopathy, a condition where the heart enlarges and weakens without blocked arteries, sudden death was the most common specific cause, representing about 18% of total deaths. By contrast, in drug-induced cardiomyopathy, cardiovascular death was responsible for only 25% of deaths, with non-cardiovascular causes dominating.³

Patients with ischemic heart failure also face higher overall mortality compared with those whose heart failure has non-ischemic origins. Among patients with implantable defibrillators, those with ischemic cardiomyopathy had roughly 1.8 times the all-cause mortality of non-ischemic patients, despite similar rates of dangerous arrhythmias between the two groups.¹⁰ The arrhythmia rates were virtually identical at about 15–16% over three and a half years, but the ischemic group died more often from both cardiac and non-cardiac causes. This suggests that the excess mortality in ischemic heart failure is not just about rhythm problems but reflects the broader vascular disease burden these patients carry.

Age and Sex Differences

Age reshapes the cause-of-death profile in ways that clinicians and families should understand. Among patients with preserved ejection fraction, sudden death was proportionally the most common way to die in those aged 55 and younger. In patients 85 and older, non-cardiovascular causes took over, accounting for 34% of deaths compared with 20% in the youngest group.¹¹ Older patients simply have more competing risks: cancer, dementia, kidney failure, and serious infections all become more likely with advancing age, and any of them can become the final event even in someone with significant heart failure.

Sex differences also emerge clearly in the data. Men with heart failure consistently have higher mortality rates than women. An analysis of U.S. CDC data from 1999 to 2019 found that age-adjusted heart failure mortality rates were higher in men across every age group, and that after a period of declining mortality in both sexes through about 2012, rates began climbing again.¹² Among elderly patients with systolic heart failure specifically, male sex was an independent risk factor for death, roughly doubling the hazard even after adjusting for blood pressure, diabetes, kidney function, and medications.¹³

The Growing Role of Non-Cardiovascular Death

As treatments for heart failure have improved, a quiet shift has occurred: more patients are surviving long enough for non-cardiovascular diseases to catch up with them. Kidney disease is one of the most consequential. Heart failure and kidney failure form a vicious cycle, sometimes called cardiorenal syndrome, where each organ’s decline accelerates the other’s.¹⁴ When anemia enters the picture alongside heart and kidney problems, the combination is particularly dangerous. Patients with all three conditions had roughly double the mortality of those without the triad, and the combination was an independent predictor of death.¹⁵

Infections are another underappreciated threat. In the ALARM-HF registry, infection was one of the most frequent triggers of acute heart failure episodes, present in about 19% of patients with a prior history of heart failure flares and 12% of those with new-onset heart failure.¹⁶ Pneumonia and urinary tract infections are common culprits. For a failing heart already operating at its limits, the additional metabolic demand of fighting an infection can be enough to cause a fatal decompensation.

Polypharmacy, the simultaneous use of many medications, adds another layer of risk. In a study of hospitalized heart failure patients, overall polypharmacy was associated with about a 31% increase in mortality risk, even though taking many cardiovascular medications alone was not. The danger seems to come from the cumulative burden of drug interactions, side effects, and the non-cardiovascular conditions that necessitate all those extra prescriptions.¹⁷

Predicting Who Dies How

Researchers have spent years trying to build models that can predict whether a given heart failure patient is more likely to die suddenly or from pump failure, because the prevention strategies are so different. The challenge is that many of the same risk factors, like poor functional status and low ejection fraction, predict both. Still, some signals help separate the two.

Clinical variables alone can stratify patients into groups where the high-risk patients face more than four times the hazard of sudden death or pump failure compared with low-risk patients. When ECG-based markers, particularly measures of electrical instability in the heart, are added to the model, the separation improves substantially. One integrated risk model found that combining clinical and ECG markers produced hazard ratios above 13 for both sudden death and pump failure when comparing the highest-risk group against the lowest.¹⁸

Blood-based biomarkers have also shown promise. ST2 and galectin-3, both markers of heart muscle stress and scarring, improved the ability to classify who would die suddenly by about 11%, though they did not improve prediction of pump failure death.¹⁹ NT-proBNP, a hormone released when the heart is under strain, substantially improved sudden death prediction in patients with preserved ejection fraction, a group where risk stratification has traditionally been difficult.²⁰ Despite this progress, no model yet performs well enough to definitively tell a patient or their family which type of death is coming. The predictions remain probabilistic, not certain.

Where Heart Failure Patients Die

The physical location of death in heart failure has changed dramatically. In the United States, deaths at home nearly doubled between 1999 and 2023, rising from about 18% to 33%. Hospice and nursing home deaths rose through 2017, then declined somewhat. Hospital deaths, long the dominant setting, have been falling.²¹ This shift reflects broader changes in how end-of-life care is delivered, including greater use of hospice services and growing patient preference for dying at home rather than in an ICU.

End-of-life care in heart failure is uniquely difficult because the disease trajectory is unpredictable. Unlike cancer, which often follows a relatively steady decline, heart failure tends to involve repeated crises followed by partial recovery, making it hard for patients and clinicians to identify when the final decline has begun. Many patients do not perceive the terminal nature of their illness until very late. In one study of Stage D (advanced) heart failure patients, most did not recognize they were dying before their final hospitalization, and actual survival was often far shorter than what prediction models had estimated.²² Symptom control during the dying process, including management of breathlessness, pain, anxiety, and nausea, is an important issue that often gets too little attention in a disease traditionally managed by cardiologists focused on keeping the heart going.²³

Global Disparities in Heart Failure Mortality

Where you live changes your odds dramatically. A large international study found that mortality rates in lower-middle-income and low-income countries were more than double those in high-income countries. In low-income settings, deaths actually outnumbered hospitalizations, a reversal of the pattern seen in wealthy nations where patients are hospitalized repeatedly but survive each episode. The short-term risk of death during a heart failure hospitalization was three to five times higher in low-income countries compared with high-income ones.²⁴

These gaps are driven by differences in access to medications, diagnostic tools, specialized cardiologists, and intensive care. In many low-resource settings, patients present later in the disease course, have limited access to the guideline-recommended drugs that reduce sudden death and slow pump failure, and may not have access to defibrillators or advanced surgical options at all. The causes of heart failure also differ globally: rheumatic heart disease and untreated hypertension remain major drivers in sub-Saharan Africa and South Asia, whereas coronary artery disease dominates in North America and Europe. These etiological differences further shape the cause-of-death profile, because the type of heart damage influences whether pump failure or arrhythmia is the likelier endpoint.