Recent Australian research has highlighted pericardial fat as an underestimated risk factor for heart problems. In a study published in Heart, Lung and Circulation, researchers used cardiac CT scans to measure epicardial adipose tissue—the fat that sits between the heart muscle and its outer lining. People with larger volumes of this fat had stiffer hearts and worse diastolic function, even after accounting for overall body size, changes that increase the likelihood of developing heart failure.
A separate longitudinal study from Monash University followed adults for around five years and found that increases in epicardial adipose tissue over time were linked with worsening heart structure and rising cardiometabolic risk factors.
Heart failure is a chronic condition in which the heart cannot pump enough blood to meet the body’s needs. It affects hundreds of thousands of Australians and is a major cause of hospital admissions in older adults.
What have researchers found about pericardial fat?
International imaging studies show a clear pattern: once pericardial fat creeps above a certain volume, the risk of heart failure climbs sharply. Even though women often have less pericardial fat than men overall, research suggests that when women move into the “high” range, their risk can almost double compared to women with lower volumes. Men with high pericardial fat also face a substantially higher risk.
Crucially, that risk seems to hold regardless of body weight. People in the healthy-weight range can still carry excess fat around the heart, so a lower number on the scales does not necessarily rule out harmful fat build-up in this area.
When researchers adjust for other major heart failure risks such as age, smoking, alcohol intake, limited physical activity, high blood pressure, high cholesterol and a history of heart attack, the link between high pericardial fat and heart failure largely remains. Similar patterns appear across different ethnic backgrounds.
Why is fat around the heart such a problem?
“Pericardial fat is a specific type of fat that sits around the heart, particularly between the outer layers of the pericardium, the sac that encases the heart,” says preventive cardiologist Dr Danielle Belardo. “It includes both epicardial fat, which is directly on the heart’s surface, and paracardial fat just outside the pericardium.
Pericardial fat is metabolically active, meaning it doesn’t just sit there. It secretes inflammatory substances that can directly affect the heart muscle and nearby coronary arteries. Essentially, this type of fat is a marker, and possibly a driver, of cardiometabolic disease.”
When extra fat surrounds the heart, fatty droplets can start to accumulate inside the heart muscle cells, explains cardiologist Dr Satish Kenchaiah. These deposits can interfere with how the heart chamber relaxes and fills, and can reduce the heart’s ability to pump blood properly, setting the scene for heart failure.
A fatty heart is also linked with plaque build-up in the coronary arteries that feed the heart muscle. That raises the risk of heart attack, which can in turn increase the chance of developing heart failure later on.
Although the original work on pericardial fat and heart failure was published a few years ago, Belardo notes that the message is even more relevant now, with rising rates of obesity, type 2 diabetes and metabolic dysfunction worldwide.
How to reduce pericardial fat
Dr Kenchaiah, notes that more research is needed to work out the best way to specifically target pericardial fat, but habits that protect overall heart health are the strongest starting point. He recommends:
- Following a Mediterranean-style pattern of eating. Focus on colourful fruit and vegetables, fibre-rich wholegrains and legumes, extra-virgin olive oil, nuts and seeds and mostly lean proteins such as seafood and poultry.
- Moving regularly. Aim for at least 150 minutes of moderate activity such as brisk walking or 75 minutes of vigorous exercise such as running spread across the week, plus muscle-strengthening work on most days.
- Keeping alcohol in check. Avoid drinking more than national guidelines recommend and build in alcohol-free days.
- Managing key risk factors early. Work with a doctor to bring down high blood pressure, high blood sugar or high cholesterol, as all of these raise the risk of heart disease and heart failure.
When to see your doctor
“Pericardial fat itself does not cause symptoms. It acts as an inflammatory organ that increases risk for heart failure, coronary artery disease and arrhythmias,” says Dr Belardo. Symptoms of heart failure, which may develop over time in people with high pericardial fat, can include:
- Shortness of breath with activity or when lying flat
- Fatigue or reduced exercise tolerance
- Swollen ankles, legs or abdomen
- Rapid weight gain related to fluid retention
- Persistent cough or wheeze
Anyone with these symptoms, or with obesity, prediabetes, diabetes, high cholesterol, hypertension or metabolic syndrome, or a family history of heart failure or early cardiovascular disease, should see a doctor promptly. “Cardiac imaging, blood tests and early preventive care can be crucial for catching heart disease before symptoms develop,” Belardo explains.
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