Pulmonary hypertension common in heart dysfunction patients
Enlarged left atrium, irregular heartbeat make condition more likely
Nearly two-thirds of patients with left ventricular diastolic dysfunction (LVDD) — in which the heart struggles to relax and fill with blood between heartbeats — also have pulmonary hypertension, a study found, and the condition is more likely if a person has an enlarged left atrium (the heart’s upper left chamber), an irregular heartbeat, or is older.
The study of more than 16,000 adults in Australia also found that being older, female, and having a lower left ventricular ejection fraction (LVEF) — the percentage of blood pumped out to the body with each heartbeat — were all linked to more severe pulmonary hypertension.
“This provides clinicians with a framework for risk classification and long-term monitoring for patients,” the researchers wrote in the study, “Characteristics of pulmonary hypertension in adults with left ventricular diastolic dysfunction,” published in Heart Failure and Cardiomyopathies.
LVDD occurs when the left ventricle, the heart’s bottom left chamber, doesn’t relax and fill with blood properly. This can raise blood pressure in the vessels that carry blood from the heart to the lungs, leading to pulmonary hypertension — a “common and serious complication,” the researchers wrote.
The factors that influence how common or severe pulmonary hypertension is in patients with LVDD are not well understood. To study this, the researchers analyzed data from 16,058 adults in Australia, mean age 73, who had LVDD but a preserved LVEF (above 50%).
Heart rhythm, pressure measured
More than half of the patients (57.4%) were women, and 2,503 (15.6%) had atrial fibrillation — an irregular heartbeat — while the rest had a normal heart rhythm. Nearly two-thirds (62.1%) had pulmonary hypertension, defined as a peak tricuspid regurgitation velocity — a measure of pressure on the right side of the heart — of 2.9 m/s or higher on a heart ultrasound.
Having atrial fibrillation and an enlarged right ventricle were the strongest risk factors for pulmonary hypertension, with odds being 1.27 times higher with atrial fibrillation and nearly five times higher with an enlarged right ventricle. Being older or having a lower LVEF also increased the risk for pulmonary hypertension.
As tricuspid regurgitation velocity increased, the size of the left atrium, measured using the left atrium volume index LAVi), also increased. While it leveled off at the highest levels, “LAVi is the parameter most closely correlated to progressively rising pulmonary pressures,” the researchers wrote.
Having atrial fibrillation, an enlarged right ventricle, and being female or older were linked to more severe pulmonary hypertension, defined as an increase in peak tricuspid regurgitation velocity. A lower E/e’ ratio, a measure of filling pressure into the left ventricle, was linked to less severe pulmonary hypertension.
The researchers said the study was likely the largest of its kind.
In addition to helping clinicians assess risk for pulmonary hypertension and better manage PH symptoms, knowing what factors contribute to the disease also “allows future studies to use these as potential therapeutic targets,” they wrote.
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