Abnormal pulmonary artery pressure profile after cardiac transplantation: an exercise Doppler echocardiographic study

Estimated right ventricular systolic pressure during exercise stress echocardiography in patients with suspected coronary artery disease

OBJECTIVE

To determine the normal range of estimated right ventricular systolic pressure (RVSP) at peak exercise during exercise stress echocardiography (ExECHO) in a series of consecutive patients referred for the investigation of coronary artery disease.

METHODS

Of 1057 ExECHO examinations over a span of 11 months, 807 met the study criteria. A total of 250 patients were excluded, 188 for missing rest or peak RVSP measurements, 16 for a resting RVSP above 50 mmHg, 16 for nondiagnostic echocardiographic images and the remaining 30 for missing data. The maximal tricuspid regurgitant jet was recorded at rest and following acquisition of the stress images (mean [+/- SD] time 103.1+/-35.2 s). A mean right atrial pressure of 10 mmHg was used in the calculation of RVSP. All data were entered into a cardiology database (CARDIOfile; Registered trademark, Kingston Heart Clinic) for later retrieval and analysis.

RESULTS

There were 206 male (58.9+/-12.0 years of age) and 601 female patients (57.4+/-12.0 years of age). Patient age ranged from 18 to 90 years. The mean resting and peak exercise RVSP was 27.8+/-7.8 mmHg and 34.8+/-11.3 mmHg in men, and 27.8+/-7.7 mmHg and 34.6+/-11.7 mmHg in women, respectively. The mean increase in RVSP was 7.0+/-8.8 mmHg in men and 6.7+/-8.9 mmHg in women. The 95% CI for peak RVSP was 12.2 mmHg to 57.4 mmHg in men, and 11.2 mmHg to 58.0 mmHg in women. There was no significant difference in peak RVSP for a normal ExECHO compared with an abnormal ExECHO. RVSP at rest and at peak exercise increased with both age and left atrial size.

CONCLUSIONS

In individual patients, the RVSP should not increase above the resting value by more than 24.6 mmHg in men and 24.5 mmHg in women. This value was calculated as the increase in RVSP plus 2xSD of the RVSP. Peak RVSP should not exceed 57.4 mmHg in men and 58.0 mmHg in women. If either of these criteria is exceeded, the response of RVSP to exercise should be considered abnormal.

Diagnosis and assessment of pulmonary arterial hypertension

The diagnosis and assessment of pulmonary arterial hypertension is a rapidly evolving area, with changes occurring in the definition of the disease, screening and diagnostic techniques, and staging and follow-up assessment. The definition of pulmonary hypertension has been simplified, and is now based on currently available evidence. There has been substantial progress in advancing the imaging techniques and biomarkers used to screen patients for the disease and to follow up their response to therapy. The importance of accurate assessment of right ventricular function in following up the clinical course and response to therapy is more fully appreciated. As new therapies are developed for pulmonary arterial hypertension, screening, prompt diagnosis, and accurate assessment of disease severity become increasingly important. A clear definition of pulmonary hypertension and the development of a rational approach to diagnostic assessment and follow-up using both conventional and new tools will be essential to deriving maximal benefit from our expanding therapeutic armamentarium.

Abnormal pulmonary artery pressure response in asymptomatic carriers of primary pulmonary hypertension gene

BACKGROUND

Familial primary pulmonary hypertension (PPH) is an autosomal-dominant inherited disease with incomplete penetrance and poor prognosis. This study was performed to examine whether asymptomatic carriers of a mutated PPH gene can be identified at an early stage by their pulmonary artery systolic pressure (PASP) response to exercise.

METHODS AND RESULTS

Stress Doppler echocardiography during supine bicycle exercise and genetic linkage analysis were performed on 52 members of 2 families with PPH. In 4 PPH patients, the mean PASP was increased at rest (73+/-16 mm Hg). Fourteen additional family members with normal PASP at rest revealed an abnormal PASP response to exercise (from 23+/-4 to 56+/-11 mm Hg) without secondary cause (abnormal response [AR] group). Twenty-seven other members (NR group) revealed a normal PASP response (maximal pressure <40 mm Hg) to exercise (from 24+/-4 to 37+/-3 mm Hg, P<0. 0001). All 14 AR but only 2 NR members shared the risk haplotype with the PPH patients. The molecular genetic analysis supported linkage to chromosome 2q31-32 with a logarithm of the odds score of 4.4 when the 4 patients and the 14 AR members were classified as affected.

CONCLUSIONS

We conclude that the pathological rise of PASP in asymptomatic family members is linked to chromosome 2q31-32 and is probably an early sign of PPH. Therefore, stress Doppler echocardiography may be a useful tool to identify persons at risk for PPH even before pulmonary artery pressures at rest are elevated.