Classification and epidemiology of pulmonary hypertension

Plasma Connective Tissue Growth Factor as a Biomarker of Pulmonary Arterial Hypertension Associated With Congenital Heart Disease in Adults

BACKGROUND

Connective tissue growth factor (CTGF) has diagnostic value for pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD) in children; however, its value in adult patients remains unclear. This study evaluated CTGF as a biomarker in adult PAH-CHD patients.Methods and Results: Based on mean pulmonary artery pressure (mPAP), 56 CHD patients were divided into 3 groups: without PAH (W; mPAP <25 mmHg; n=28); mild PAH (M; mPAP 25-35 mmHg; n=18); and moderate and severe PAH (H; mPAP ≥35 mmHg; n=10). The control group consisted of 28 healthy adults. Plasma CTGF and B-type natriuretic peptide (BNP) concentrations were determined. Plasma CTGF concentrations were higher in the H and M groups than in the W and control groups, and were higher in the H than M group. Plasma CTGF concentrations were positively correlated with pulmonary artery systolic pressure (PASP), mPAP, and pulmonary vascular resistance, and negatively correlated with mixed venous oxygen saturation. CTGF, BNP, red blood cell distribution width, and World Health Organization Class III/IV were risk factors for PAH in CHD patients, and CTGF was an independent risk factor for PAH-CHD. The efficacy of CTGF in the diagnosis of PAH was not inferior to that of BNP.

CONCLUSIONS

CTGF is a biomarker of PAH associated with CHD. It can be used for early diagnosis and severity assessment in adult patients with CHD-PAH.

Biomarkers for Bronchopulmonary Dysplasia in the Preterm Infant

Bronchopulmonary dysplasia (BPD) is a chronic inflammatory lung disease of very-low-birth-weight (VLBW) preterm infants, associated with arrested lung development and a need for supplemental oxygen. Over the past few decades, the incidence of BPD has significantly raised as a result of improved survival of VLBW infants requiring mechanical ventilation. While early disease detection is critical to prevent chronic lung remodeling and complications later in life, BPD is often difficult to diagnose and prevent due to the lack of good biomarkers for identification of infants at risk, and overlapping symptoms with other diseases, such as pulmonary hypertension (PH). Due to the current lack of effective treatment available for BPD and PH, research is currently focused on primary prevention strategies, and identification of biomarkers for early diagnosis, that could also represent potential therapeutic targets. In addition, novel histopathological, biochemical, and molecular factors have been identified in the lung tissue and in biological fluids of BPD and PH patients that could associate with the disease phenotype. In this review, we provide an overview of biomarkers for pediatric BPD and PH that have been identified in clinical studies using various biological fluids. We also present a brief summary of the information available on current strategies and guidelines to prevent and diagnose BPD and PH, as well as their pathophysiology, risk factors, and experimental therapies currently available.

Clinical efficacy of phosphodiesterase-5 inhibitor tadalafil in Eisenmenger syndrome--a randomized, placebo-controlled, double-blind crossover study

OBJECTIVES

In a randomized double-blind crossover trial, we compared the efficacy of phosphodiesterase-5 (PDE-5) inhibitor tadalafil with placebo in patients of Eisenmenger Syndrome (ES). The primary end point was the change in 6-minute walk test distance (6 MWD). Secondary end points were the effect of the drug on systemic oxygen saturation (SO(2) ), pulmonary vascular resistance (PVR), systemic vascular resistance (SVR), effective pulmonary blood flow (EPBF), and World Health Organization (WHO) functional class.

BACKGROUND

ES is a disorder with limited treatment options. Uncontrolled studies have shown PDE-5 inhibitors to be beneficial in patients of ES.

METHODS

Twenty-eight symptomatic adult patients of ES with weight ≥30 kg in WHO class II and III were enrolled. Patients were given 40 mg of tadalafil or matching placebo for 6 weeks followed by crossover to the other drug after a washout period of 2 weeks. Assessment of WHO class, exercise capacity by 6 MWD, and various hemodynamic parameters by cardiac catheterization was done at baseline, after 6 weeks and at the end of the study.

RESULTS

All patients completed the study. There was significant increase in 6 MWD following drug administration compared with baseline (404.18 ± 69.54 m vs. 357.75 ± 73.25 m, P < .001). Compared with placebo, tadalafil produced significant decrease in PVR (-7.32 ± 1.58, P < .001), resulting in significant increase in EPBF (0.12 ± 0.05, P= .03), SO(2) % (1.72 ± 0.58, P= .007), and WHO functional class (1.96 ± 0.18 vs. 2.14 ± 0.44, P= .025), with no significant change in SVR (P= NS).

CONCLUSION

In this first short-term placebo-controlled trial of tadalafil in patients of ES, the drug was well tolerated and significantly improved exercise capacity, functional class, SO(2) , and pulmonary hemodynamics.

Pregnancy outcomes in systemic sclerosis, primary pulmonary hypertension, and sickle cell disease

OBJECTIVE

Systemic sclerosis, primary pulmonary hypertension, and sickle cell disease are uncommon vasculopathic diseases affecting women. We estimated the nationwide occurrence of pregnancies in women with these conditions and compared pregnancy outcomes to the general obstetric population.

METHODS

We studied the 2002-2004 Nationwide Inpatient Sample, of the Healthcare Cost and Utilization Project to estimate the number of obstetric hospitalizations and deliveries among women with systemic sclerosis, primary pulmonary hypertension, sickle cell disease, and women in the general population. Pregnancy outcomes included length of hospital stay, hypertensive disorders including preeclampsia, intrauterine growth restriction (IUGR), and cesarean delivery. Multivariable regression analyses were performed using maternal age, race or ethnicity, antiphospholipid antibody syndrome, diabetes mellitus, and renal failure as covariates.

RESULTS

Of an estimated 11.2 million deliveries, 504 occurred in women with systemic sclerosis, 182 with primary pulmonary hypertension, and 4,352 with sickle cell disease. Systemic sclerosis, was associated with an increased risk of hypertensive disorders including preeclampsia (odds ratio [OR] 3.71, 95% confidence interval [CI] 2.25-6.15), IUGR (OR 3.74, 95% CI 1.51-9.28), and increased length of hospital stay. Primary pulmonary hypertension was associated with an increase in the odds of antenatal hospitalization (OR 4.67, 95% CI 2.88-7.57), hypertensive disorders including preeclampsia (OR 5.62, 95% CI 2.60-12.15) and a substantial increase in length of hospital stay. Sickle cell disease was associated with an increased odds of antenatal hospitalization (OR 5.56 95% CI 5.08-6.09), hypertensive disorders including preeclampsia (OR 1.78, 95% CI 1.48-2.14), and IUGR (OR 2.91, 95% CI 2.16-3.93), with a modest increase in length of hospital stay.

CONCLUSION

Women with systemic sclerosis, primary pulmonary hypertension, and sickle cell disease have significantly increased rates of adverse pregnancy outcomes, requiring extensive preconceptional counseling about the risks of pregnancy.

Chronic intermittent hypoxia at high altitude exposure for over 12 years: assessment of hematological, cardiovascular, and renal effects

The aim of this cross-sectional study was to assess the health status of subjects weekly commuting between sea level and 3550-m altitude for at least 12 yr (average 22.1 +/- 5.8). We studied 50 healthy army men (aged 48.7 +/- 2.0) working 4 days in Putre at 3550-m altitude, with 3 days rest at sea level (SL) at Arica, Chile. Blood pressure, heart rate, Sa(O(2) ), and altitude symptoms (AMS score and sleep status) were measured at altitude (days 1, 2, and 4) and at SL (days 1, 2, and 3). Hematological parameters, lipid profile, renal function, and echocardiography were performed at SL on day 1. The results showed signs of acute exposure to hypoxia (tachycardia, high blood pressure, low Sa(O(2) )), AMS symptoms, and sleep disturbances on day 1, which rapidly decreased on day 2. In addition, echocardiographic findings showed pulmonary hypertension (PAPm > 25 mmHg, RV and RA enlargement) in 2 subjects (4%), a PAPm > 20 mmHg in 14%, and a right ventricle thickness >40 mm in 12%. Hematocrit (45 +/- 2.7) and hemoglobin (15 +/- 1.0) were elevated, but lower than in permanent residents. There was a remarkably high triglyceride level (238 +/- 162) and a mild decrease of glomerular filtration rate (34% under 90 mL/min and 8% under 80 mL/min of creatinine clearance). In conclusion, in these preliminary results, in chronic intermittent hypoxia exposure even over longer periods, most subjects still show symptoms of acute altitude illnesses, but a faster recovery. Findings in triglycerides, in the pulmonary circulation and in renal function, are also a matter of concern.

Decreased left ventricular function, myocarditis, and coronary arteriolar medial thickening following monocrotaline administration in adult rats

Decreased right as well as left ventricular function can be associated with pulmonary hypertension (PH). Numerous investigations have examined cardiac function following induction of pulmonary hypertension with monocrotaline (MCT) assuming that MCT has no direct cardiac effect. We tested this assumption by examining left ventricular function and histology of isolated and perfused hearts from MCT-treated rats. Experiments were performed on 50 male Sprague-Dawley rats [348 +/- 6 g (SD)]. Thirty-seven rats received MCT (50 mg/kg sc; MCT group) while the remainder did not (Control group). Three weeks later, pulmonary artery pressure was assessed echocardiographically in 20 MCT and 8 Control rats. The hearts were then excised and perfused in the constant pressure Langendorff mode to determine peak left ventricular pressure (LVP), the peak instantaneous rate of pressure increase (+dP/dtmax) and decrease (-dP/dtmax), as well as the rate pressure product (RPP). Histological sections were subsequently examined. Pulmonary artery pressure was higher in the MCT-treated group compared with the Control group [12.9 +/- 6 vs. 51 +/- 35.3 mmHg (P < 0.01)]. Left ventricular systolic function and diastolic relaxation were decreased in the MCT group compared with the Control group (+dP/dtmax 4,178 +/- 388 vs. 2,801 +/- 503 mmHg/s, LVP 115 +/- 11 vs. 83 +/- 14 mmHg, RPP 33,688 +/- 1,910 vs. 23,541 +/- 3,858 beats x min(-1) x mmHg(-1), -dP/dtmax -3,036 +/- 247 vs. -2,091 +/- 389 mmHg/s; P < 0.0001). The impairment of cardiac function was associated with myocarditis and coronary arteriolar medial thickening. Similarly depressed ventricular function and inflammatory infiltration was seen in 12 rats 7 days after MCT administration. Our findings appear unrelated to the degree of PH and indicate a direct cardiotoxic effect of MCT.

Phosphodiesterase-5 Inhibitor in Eisenmenger Syndrome

Background— Phosphodiesterase-5 inhibitors produce a significant decrease in pulmonary vascular resistance in patients with idiopathic pulmonary arterial hypertension. We studied the effects of tadalafil, a phosphodiesterase-5 inhibitor, on short-term hemodynamics, tolerability, and efficacy over a 12-week period in patients of Eisenmenger syndrome having a pulmonary vascular pathology similar to idiopathic pulmonary arterial hypertension.

Methods and Results— Sixteen symptomatic Eisenmenger syndrome patients (mean age, 25±8.9 years) were assessed hemodynamically at baseline and 90 minutes after a single dose of tadalafil (1 mg/kg body weight up to a maximum of 40 mg). The same dose was then continued daily for 12 weeks, and the patients were restudied. There was a significant decrease in mean pulmonary vascular resistance immediately (24.75±8.49 to 19.22±8.23 Woods units; P <0.005) and at 12 weeks (19.22±8.23 to 17.02±6.19 Woods units; P =0.03 versus 90 minutes). Thirteen of 16 patients (81.25%) showed a ≥20% decrease in pulmonary vascular resistance and were defined as responders. The mean systemic oxygen saturation improved significantly both immediately (84.34±5.47% to 87.39±4.34%; P <0.005) and at 12 weeks (87.39±4.34% to 89.16±3.8%; P <0.02 versus 90 minutes) without a significant change in systemic vascular resistance. None of the patients had a fall in systemic arterial pressure, worsening of systemic oxygen saturation, or any adverse reactions to the drug. The mean World Health Organization functional class improved from 2.31±0.47 to 1.25±0.44 ( P <0.0001), and the 6-minute walk distance improved from 344.56±119.06 to 387.56±117.18 m ( P <0.001).

Conclusions— Preliminary evaluation of tadalafil has shown efficacy and safety in selected patients with Eisenmenger syndrome, warranting further investigation in this subgroup of patients.