Significant Clinical Indexes of Exercise-Induced Pulmonary Hypertension in Patients With Connective Tissue Disease

Exercise-Induced Pulmonary Hypertension: A Valid Entity or Another Factor of Confusion?

Exercise-induced pulmonary hypertension EIPH has been defined as an increase in mean pulmonary arterial pressure (mPAP) during exercise in otherwise normal values at rest. EIPH reflects heart and/or lung dysfunction and may precede the development of manifest pulmonary hypertension (PH) in a proportion of patients. It is also associated with decreased life expectancy in patients with heart failure with reduced ejection fraction (HFrEF) or left ventricle (LV) valvular diseases. Diastolic dysfunction exacerbated during exercise relates to increased LV filling pressure and left atrial pressure (LAP). In this context backward, transmitted pressure alone or accompanied with backward blood flow promotes EIPH. The gold standard of EIPH assessment remains the right heart catheterization during exercise, which is an accurate but invasive method. Alternatively, non-invasive diagnostic modalities include exercise stress echocardiography (ESE) and cardiopulmonary exercise testing (CPET). Both diagnostic tests are performed under gradually increasing physical stress using treadmill and ergo-cycling protocols. Escalating workload during the exercise is analogous to the physiological response to real exercise. The results of the latter techniques show good correlation with invasive measurements, but they suffer from lack of validation and cut-off value determination. Although it is not officially recommended, there are accumulated data supporting the importance of EIPH diagnosis in the assessment of other mild/subclinical or probably fatal diseases in patients with latent PH or heart failure or LV valvular disease, respectively. Nevertheless, larger, prospective studies are required to ensure its role in clinical practice.

Evaluation of pulmonary arterial pressure in patients with connective tissue disease-associated pulmonary arterial hypertension by myocardial perfusion imaging

BACKGROUND

Pulmonary arterial hypertension (PAH) is a complex and severe complication of connective tissue disease (CTD). We aimed to evaluate the application value of myocardial perfusion imaging (MPI) in evaluating CTD-associated PAH (CTD-PAH).

METHODS

We retrospectively included 88 patients who were diagnosed with CTD between January 2018 and December 2020 at our hospital. Fifty-eight patients had PAH and were included into the CTD-PAH group. Thirty patients without PAH were included in the control group. All patients received routine physical examination, biochemical tests and cardiac function evaluation, right heart catheterization (RHC), and ^99m Tc-MIBI MPI. PAH patients were divided into the mild, moderate, and severe PAH group according to their mean pulmonary artery pressures by RHC. Pearson correlation analysis was used to calculate the correlation between the right ventricle target/background (T/B) and right ventricle stroke volume (RV-SV), total pulmonary resistance (TPR), pulmonary vascular resistance (PVR), mean pulmonary arterial pressure (mPAP), 6-minute walk distance (6-MWD), and N-terminal B-type natriuretic peptide (NT-proBNP). The ROC curves of T/B and pulmonary artery pressure classification were plotted and the sensitivity and specificity of T/B in diagnosing PAH of different severities were analyzed.

RESULTS

The analysis of correlation revealed that T/B correlated negatively with 6-MWD and positively with NT-proBNP and exhibited good positive correlation with mPAP, TPR, and PVR by RHC and negative correlation with RV-SV. T/B was of the most diagnostic value for severe PAH, and its correlation with severe PAH was stronger than that with mild PAH and moderate PAH.

CONCLUSIONS

Target/background is a noninvasive method that can simultaneously evaluate pulmonary arterial pressure and myocardial perfusion of CTD-CHD patients and is particularly of relatively high value for severe PAH patients.

Exercise-induced pulmonary hypertension in HIV patients: Association with poor clinical and immunological status

BACKGROUND AND AIM

Exercise-induced pulmonary hypertension (Ex-PH) may represent the earliest sign of pulmonary arterial hypertension (PAH) in human immunodeficiency virus (HIV) patients. We investigated its association with clinical and immunological status, virologic control, and response to antiviral therapy.

METHODS

In 32 consecutive HIV patients with either low (n = 29) or intermediate probability (n = 3) of PH at rest, we evaluated the association of isolated ExPH with: time to HIV diagnosis; CD4+ T-cell count; clinical progression to acquired immunodeficiency syndrome (AIDS); development of resistance to antiretroviral therapy (ART); HIV RNA levels; time to beginning of ART; current use of protease inhibitors; combination of ART with boosters (ritonavir or cobicistat); immuno-virologic response to ART; and ART discontinuation. Isolated ExPH at stress echocardiography (ESE) was defined as absence of PH at rest and systolic pulmonary arterial pressure (sPAP) >45 mmHg or a >20 mmHg increase during low-intensity exercise cardiac output (<10 L/min).

RESULTS

In our cohort, 22% (n = 7) of the enrolled population developed ExPH which was inversely related to CD4+ T-cell count (p = 0.047), time to HIV diagnosis (p = 0.014) and time to onset of ART (p = 0.041). Patients with ExPH had a worse functional class than patients without ExPH (p < 0.001). ExPH and AIDS showed a trend (p = 0.093) to a direct relationship. AIDS patients had a higher pulmonary vascular resistance compared to patients without ExPH (p = 0.020) at rest echocardiography.

CONCLUSIONS

The presence of isolated ExPH associates with a worse clinical status and poor immunological control in HIV patients. Assessment of ExPH by ESE may help identify subgroups of HIV patients with a propensity to develop subclinical impairment of pulmonary circulation following poor control of HIV infection.