Background:
The true prevalence of left heart disease among patients with pulmonary hypertension (PH) (classified as group II) has not been well investigated. These include patients with left ventricular (LV) systolic or diastolic dysfunction or valve abnormalities. We sought to investigate the prevalence and specific causes of group II PH in patients referred for echocardiography.
Methods:
All transthoracic echocardiograms (TTE) performed from 1991 to 2014 at our center were analyzed. Adult patients with tricuspid incompetence gradient (TIG) ≥50 mmHg were evaluated for features of left heart disease and divided into 4 groups: (1) LV systolic dysfunction (≥moderate) (2) significant mitral or aortic valve disease (3) combined LV systolic and valve dysfunction (4) diastolic dysfunction defined as impaired relaxation or grade III-IV or combination of left atrial enlargement (≥4.5cm) with thickened interventricular septum (≥1.4cm) without LV systolic dysfunction or valve disease.
Results:
Of TTEs in 63,143 patients, 5719 (9%) had elevated TIG. Mean age was 75±13 years (55% females). Median TIG was 56mmHg (IQR 52, 63), without difference between group II and non-group II patients. The proportion of group II PH and the above defined sub-groups is illustrated in the figure. Specific causes of left heart disease were LV systolic dysfunction in 18.6%, mitral regurgitation in 39.6%, mitral stenosis in 4.6%, aortic regurgitation in 2.3%, aortic stenosis in 8.5% and diastolic dysfunction in 17.2%.
Conclusion:
Elevated TIG has found in 9% of patients referred for transthoracic echocardiography. The majority (72%) have left heart disease (group II PH). Of those, half have significant valve abnormalities with mitral regurgitation being the most prevalent. These findings confirm that left heart disease is the predominant cause of elevated TIGs and call to intensify diagnostic and therapeutic efforts for this group of patients.
