PH Not Common Disease, Population Study Finds, but Groups at Risk
The likelihood of developing pulmonary hypertension (PH) is low among people in southern Italy, suggests a study that draws from a random and large grouping of individuals with echocardiograms, done to determine disease prevalence.
Independent predictors of PH include female sex and right ventricular enlargement, its scientists noted.
The study, “Prevalence of Pulmonary Hypertension in an Unselected Community-Based Population: A Retrospective Echocardiographic Study—RES-PH Study,” was published in the Journal of Personalized Medicine.
PH is characterized by high blood pressure in the pulmonary arteries, the blood vessels that supply the lungs. As a result, the right side of the heart (ventricle and atrium) must work harder to pump blood, which can weaken the heart over time.
Right heart catheterization is a standard method to diagnose PH, via a flexible tube inserted into a vein in the groin, arm, or neck, and into the right heart ventricle and pulmonary artery to measure blood pressure. However, it is invasive and not suitable for large-scale populations studies on PH.
An echocardiogram is a common, non-invasive tool that uses sound waves to create moving images of the heart. It has been used in PH screening to examine the right side of the heart for enlargement or thickening due to the extra workload caused by high pulmonary arterial pressure.
The echocardiogram parameter — tricuspid regurgitation peak velocity — has also been shown to correlate with pulmonary artery systolic pressure, or the blood pressure in the pulmonary artery during a heartbeat. As such, an echocardiogram can be used to estimate arterial blood pressure in population-based studies.
Researchers based at the University of Messina and their colleagues examined echocardiogram data collected from over 6,500 people who underwent the procedure. Their intent was to estimate the overall prevalence of PH in the general population of southern Italy.
Analyzed data were collected over a two-year period from 6,513 patients, with a mean age of 57.1 years, of whom 55.3% were men. Of these, 5,674 (87.1%) had a pulmonary artery systolic pressure (PASP) of 36 mmHg or less, and were classified as unlikely to have PH.
A PASP between 37 and 50 mmHg, considered an intermediate probability of PH, was found in 559 (8.6%), and a high PH probability was seen in 280 participants (4.3%) with a PASP over 50 mmHg.
Among people with an intermediate or high probability of PH, the underlying cause in 675 (80.5%) was left heart disease, when the left heart ventricle gradually weakens, leading to an increase in pulmonary pressure.
Other causes of PH included respiratory disease in 85 (10.1%) participants, 14 (1.7%) with chronic pulmonary thromboembolic disease due to blood clots in the lungs, and 43 (5.1%) classified as other diseases. Congenital heart disease-associated PH was seen in seven people (0.8%), and 15 (1.8%) had connective tissue disease-associated PH.
Higher PASP values were more prevalent in women with co-existing conditions (comorbidities), and with coronary artery disease, and diseases of the right or left heart valves.
PH risk was also seen to be elevated in people with chronic obstructive pulmonary disease (COPD), a chronic and inflammatory disease of the lungs.
In those with an intermediate probability of PH, men and women were almost equally distributed (51.3 vs. 48.7%), whereas there was a non-significant trend for fewer men (43.2 vs. 56.8%) in the higher PH probability group.
In contrast, PASP values increased significantly with age regardless of sex.
A statistical analysis found a significant correlation between elevated PASP and a larger size of the left atrium, the right atrium, as well as the right ventricle. Higher PASP was also correlated with a lower left ventricular ejection fraction (LVEF) — the total amount of blood in the left ventricle pumped out with each heartbeat.
Independent predictors of elevated PASP were age, female sex, LVEF, enlargement of the right atrium, left atrium, and right ventricle, as well as the tricuspid annular plane systolic excursion (TAPSE), a measure of the global right ventricular function.
In those with an intermediate or high probability of PH, female sex and right ventricular enlargement (dilatation) were independent predictors of high PASP.
“In conclusion, echocardiographic PH estimation has low prevalence in our unselected population in Southern Italy, but the assessments may be higher in specific subgroups, especially in those with left ventricular dysfunction or COPD,” the scientists wrote. “Female sex and right ventricular dilatation were associated with PASP independently of heart or lung disease.”
Managing these patients “in specialized centers guarantees a high quality of care,” they added.