Pulmonary Arterial Hemodynamic Assessment by a Novel Index in Systemic Sclerosis Patients: Pulmonary Pulse Transit Time

The importance of pulmonary pulse transit time in indicating right ventricular dysfunction and pulmonary arterial stiffness in rheumatoid arthritis

SUBJECT

Rheumatoid arthritis patients are at risk of developing cardiovascular disease such as right heart failure and pulmonary hypertension (PH). Arterial stiffness can be used to assess pulmonary hemodynamics. Noninvasive approaches can also be used to assess pulmonary hemodynamics. Recently, there have been reports that pulmonary pulse transit time (PPTT) may also be a useful measure. This study aims to examine the effects of pulmonary hemodynamic alterations on PPTT in RA patients.

METHODS

Forty RA patients and 40 healthy controls were included in the study. Sociodemographic characteristics, laboratory data, and echocardiographic examinations were performed in both groups. Conventional echocardiographic examination included left and right ventricular systolic and diastolic diameters, right ventricular myocardial performance index (RVMPI), right ventricular diastolic function, estimated pulmonary artery systolic pressure (sPAP), tricuspid annular plane systolic excursion (TAPSE), pulmonary artery stiffness (PAS), and PPTT. Right ventricular diastolic and systolic volumes, right ventricular ejection fraction (RVEF), and right ventricular fractional area change (RVFAC) were determined by four-dimensional echocardiography (4DE).

RESULTS

There was no difference between the sPAP values of the patients. RVMPI and PAS were increased in RA patients compared with controls. The PPTT was shortened in RA patients and correlated with RVEF, RVFAC, RVMPI, TAPSE/sPAP, disease duration, and C-reactive protein (CRP). In univariate linear regression analysis, PPTT (p < .001) was thought to be an independent predictor of PAS. RVFAC, disease duration, and PAS were also independent predictors of PPTT.

CONCLUSION

In RA patients, PPTT may be the first evidence of early abnormalities in pulmonary vascular hemodynamics. PPTT and PAS are the values that may predict each other in RA patients. Due to its more practical application, PPTT can be used instead of PAS to assess pulmonary hemodynamics.

Pulmonary transit time has close relation with pulmonary pulse wave transit time in normal subjects

BACKGROUND

Pulmonary transit time (PTT) and pulmonary pulse wave transit time (pPTT) are useful parameters for the evaluation of cardiopulmonary circulation and vascular alterations, but their relationship remains unknown. The aim of this study was to investigate the correlation between PTT and pPTT.

METHODS

A total of 60 healthy volunteers were involved in this study. They were divided into two groups (30 participants per group): <50 years and >50 years. They all underwent Doppler echocardiography of pulmonary vein flow and contrast echocardiography with the measurement of pPTT and PTT, respectively. The correlation between PTT and pPTT was deduced.

RESULTS

Compared with Group of <50 years, there was a significant increment in left atrial volume index, left atrial pressure and pulmonary artery stiffness but a significant reduction in acceleration times of pulmonary artery flow in Group of >50 years (p < 0.05). Group >50 years had longer PTT and but reduced normalized PTT by R-R interval (NPTT), reduced normalized pPTT by R-R interval (NpPTT) than Group <50 years (p < 0.05), while there was no significant difference in pPTT between the two groups (p > 0.05). PTT and NPTT were all negatively correlated with pPTT and NpPTT. The statistically significant strongest correlation was observed between PTT and NpPTT (r = -0.886, p < 0.0001). The regression equation for them was y = 7.4396-13.095x (R²  = 0.785; p < 0.001), where x and y represent NpPTT and PTT, respectively.

CONCLUSION

PTT had close relation with pPTT in normal subjects. From the regression equation for them, we can get the value of PTT simply and easily by non-invasively measured pPTT.

Assessment of pulmonary arterial stiffness in patients with systemic sclerosis without overt pulmonary hypertension

Pulmonary hypertension (PH) is a pathophysiological disorder that may involve multiple clinical conditions and complicate most systemic diseases. Systemic sclerosis (SSc), represents the leading cause of connective tissue disease (CTD) associated with PAH. Although SSc is a rare disease, it is associated with higher morbidity and early mortality than other rheumatological diseases due to developing SSc-associated interstitial pulmonary disease (ILD) and/or pulmonary arterial hypertension (PAH). The impact of the early diagnosis on the prognosis is evident. In this context, in our study, we aimed to investigate the early changes in pulmonary vascular bed by measuring pulmonary arterial stiffness (PAS) in SSc patients without overt PAH. Sixty-two SSc patients and fifty-eight gender and age-matched, healthy subjects enrolled in this cross-sectional observational study. SSc patients were evaluated in terms of disease duration and severity. Modified rodnan skin score (mRSS) was calculated as disease severity index. Echocardiographic parameters were assessed and compared to the control group. Right ventricular (RV) diameters, systolic pulmonary artery pressure (sPAP), and right ventricle myocardial performance index (RV-MPI) were significantly higher in the SSc group compared to the control group (p < 0.05). Tricuspid annular plane systolic excursion (TAPSE) and right ventricular fractional area change (RVFAC) were significantly lower in the SSc group compared to the control group (p < 0.05). PAS value (25.5 ± 9.2 kHz/ms vs. 18.1 ± 7.4 kHz/ms, p < 0.001) was significantly higher in the SSc group than in the control group. A statistically significant positive correlation relationship was detected between the PAS value and CRP, ESR, disease duration, mRSS. According to these results, in SSc patients, PAS as an inexpensive and easily applicable echocardiographic method might serve as a marker of early detection of PAH.

Screening for Pulmonary Hypertension in Systemic Sclerosis-A Primer for Cardio-Rheumatology Clinics

Systemic sclerosis (SSc) is a rare disease, with unfavorable clinical course and prognosis, characterized by progressive multisystemic involvement. SSc associated pulmonary hypertension (SSc-PAH) and interstitial lung disease (ILD) are the most important factors for morbi-mortality in these patients, being responsible for more than 60% of total deaths. Though pulmonary arterial hypertension (PAH) is the dominant subtype seen in SSc, PH secondary to ILD, left-heart pathology, and pulmonary veno-occlusive disease (PVOD) are also possible occurrences. Initial evaluation of a SSc case is complex and should be performed with a multidisciplinary approach. Early detection of SSc-PAH is imperative, given the fact that new and effective medications are available and early treatment was shown to improve outcomes. Therefore, screening algorithms must be used adequately and in a cost-effective manner. Sensitivity and negative predictive value (NPV) are the most important performance measures in a screening test. Several algorithms were developed in the last decade (e.g., DETECT and ASIG) and demonstrated higher efficiency when compared to older algorithms. The present manuscript details the risk factors for SSc-PAH and includes a critical description of current detection algorithms, as a primer for clinicians working in the field of cardio-rheumatology.

Assessment of Pulmonary Arterial Hemodynamic and Vascular Changes by Pulmonary Pulse Transit Time in Patients with Human Immunodeficiency Virus Infection

Introduction

Pulmonary arterial hypertension and human immunodeficiency virus (HIV) infection is a well-known association. Pulmonary pulse transit time (pPTT) is a recent echocardiographic marker that might be used for evaluation of pulmonary arterial stiffness (PAS) in patients with HIV infection. We aimed to investigate whether pPTT elevated in patients with HIV infection compared to healthy controls and its association with echocardiographic indices of right ventricular functions.

Materials and Methods

Fifty HIV (+) patients from infectious disease outpatient clinics and fifty age- and sex-matched HIV (-) healthy volunteers were enrolled in this study. pPTT was measured from pulmonary vein flow velocity as the time interval between the R-wave in the electrocardiography and corresponding peak late systolic was then calculated as the mean from two separate pw-Doppler measurements.

Results

pPTT, tricuspid annular peak systolic excursion (TAPSE) and right ventricle fractional area change (FAC) were significantly lower in patients with HIV than control patients (177.1 ± 34.9 vs. 215.7 ± 35.7 msn, P < 0.001; 2.33 ± 0.28 vs. 2.19 ± 0.22, P = 0.039; 45 [4.25] vs. 41.1 [4.0], P = 0.032, respectively). pPTT was positively correlated with FAC, TAPSE and cluster of differentiation 4 count (r = 0.210; P = 0.036, r = 0.256; P = 0.041, r = 0.304; P = 0.044, respectively).

Conclusion

Our study showed that pPTT, TAPSE, and right ventricle FAC levels were lower in patients with HIV infection. pPTT is an important predictor in patients with HIV expected to develop pulmonary vascular pathology.

Prolonged pulmonary pulse transit time is associated with symptoms in patients with significant mitral stenosis and sinus rhythm

INTRODUCTION

Pulmonary pulse transit time (pPTT) is a novel noninvasive echocardiographic measure to assess pulmonary arterial hemodynamics. It has been shown to be shorter in precapillary pulmonary hypertension (PHT). Mitral stenosis (MS) is one of the causes of postcapillary PHT. We aimed to investigate pPTT in patients with MS and its relationship with symptoms.

METHODS

We included 51 patients with MS (25 were asymptomatic, NYHA I, and 26 were symptomatic, NHYA II or III), and 50 controls, and evaluated their demographic characteristics and echocardiographic variables, including pPTT.

RESULTS

Baseline characteristics, including age, sex, body mass index, and cardiovascular risk factors, were similar between the MS and the control group. The pPTT was longer in the MS group than in the control group (0.21 ± 0.08 vs 0.15 ± 0.05, P < .001). Patients with symptomatic MS had longer pPTT than asymptomatic patients (P = .005). The pPTT was positively correlated with left atrial volume index and systolic pulmonary artery pressure, and negatively with tricuspid annular plane systolic excursion (r = .432; P < .001, r = .319; P = .001, r = -.293; and P = .003, respectively).

CONCLUSION

The measurement of pPTT appears clinically relevant in patients with PHT. Further studies evaluating whether it is useful in distinguishing precapillary from postcapillary PHT are required.