Unexplained pulmonary hypertension is associated with systolic arterial hypertension in patients undergoing routine Doppler echocardiography.

STUDY OBJECTIVE: To determine the validity of the association between systemic hypertension (HTN) and unexplained pulmonary hypertension (PHTN) as identified with Doppler echocardiography.

METHODS: All patients with a reported systolic pulmonary artery pressure (SPAP) on routine Doppler echocardiography from our 1997 echocardiographic database were identified. Exclusions included all diseases known to be associated with PHTN. Of 1,174 patients, 503 had PHTN (defined as a SPAP of >/= 40 mm Hg), of whom 42 (8.4%) had unexplained PHTN. These PHTN patients were matched for age (mean [+/- SD] age, 70 +/- 11 years) with 84 randomly selected patients from the same database who had normal SPAP values and no diseases associated with PHTN.

RESULTS: The mean SPAP of those patients with unexplained PHTN was 48 +/- 9 mm Hg vs 31 +/- 5 mm Hg for those without unexplained PHTN. HTN was more prevalent in those with PHTN (98% vs 72%, respectively; p = 0.0008). Patients with unexplained PHTN had significantly higher mean systolic BP, as routinely measured at the end of the echo (154 +/- 26 vs 138 +/- 21 mm Hg, respectively; p = 0.0006), but they did not differ in diastolic BP (80 +/- 14 vs 78 +/- 11 mm Hg, respectively; p = 0.39). PHTN patients and control subjects did not differ with respect to gender (women, 74% vs 70%, respectively), race (white, 64% vs 65%, respectively), body mass index (30 +/- 8 vs 28 +/- 8 kg/m(2), respectively), or left ventricular ejection fraction (64 +/- 6% vs 63 +/- 7%, respectively). When only those with known HTN were considered, PHTN patients still had higher systolic arterial BP (155 +/- 25 vs 143 +/- 21 mm Hg, respectively; p = 0.013) and tended to be on more BP medications (1.6 +/- 1.1 vs 1.2 +/- 0.9, respectively; p = 0.09).

CONCLUSIONS: Unexplained PHTN occurs mostly in the elderly, is associated with systolic HTN, and those hypertensive patients with concomitant PHTN have higher systolic arterial pressures.