Frantz, Robert P.

Background Myocardial strain imaging is a sensitive echocardiographic technique for identifying ventricular dysfunction. The aim of this study was to describe a reference range for right ventricular ( RV ) strain in subjects without cardiopulmonary disease and to report these values from a systematic review and meta‐analysis of the current literature. Methods Prospective online measurement of RV free wall longitudinal systolic strain using speckle tracking echocardiography ( STE ) was performed in 116 subjects with normal echocardiograms and without cardiopulmonary disease or risk factors. A systematic search of studies in EMBASE and Medline reporting RV strain values was performed through February 2014. Results The mean age was 48 ± 16 years and 58% were female. Mean RV strain was −26 ± 4%. Ten studies involving a total of 486 patients met our inclusion criteria. The mean age range was 43–57 years and 59% were female. All prior studies were performed with offline strain analysis, and 9 used a GE Healthcare strain analysis software system. The weighted estimate of RV free wall strain measured using tissue Doppler imaging (4 studies) was −27 ± 1% (95% confidence interval [ CI ] −30% to −25%) and with STE (8 studies, including the current study data) −27 ± 2% (95% CI −29% to −24%), respectively. Conclusions A reference range for RV strain in subjects without cardiopulmonary disease is presented. These data may help facilitate the routine clinical measurement of RV strain in patients referred for right heart echocardiography assessment.

Pulmonary arterial hypertension (PAH) is a chronic, symptomatic, life‐threatening illness; however, it is complex, with variable expression regarding impact on quality of life (QOL). This study investigated attitudes and comfort of physicians regarding palliative care (PC) for patients with PAH and explored potential barriers to PC in PAH. An internet‐based, mixed‐methods survey was distributed to Pulmonary Hypertension Clinicians and Researchers, a professional organization within the Pulmonary Hypertension Association. Only responses from physicians involved in clinical care of patients with PAH were analyzed. Of 355 clinicians/researchers, 79 (22%) returned surveys, including 76 (21%) providers involved in clinical care. Responding physicians were mainly pulmonologists (67%), practiced in university/academic medical centers (89%), had been in practice a mean of 12 ± 7 years, cared for a median of 100 PAH patients per year, and reported a high level of confidence in managing PAH (87%), advanced PAH‐specific pharmacologic interventions (95%), and end‐of‐life care (88%). Smaller proportions were comfortable managing pain (62%) and QOL issues (78%). Most physicians (91%) reported utilizing PC consultation at least once in the prior year, primarily in the setting of end‐of‐life/active dying (59%), hospice referral (46%), or symptomatic dyspnea/impaired QOL (40%). The most frequent reasons for not referring patients to PC included nonapproval by the patient/family (51%) and concern that PC is “giving up hope” (43%). PAH may result in symptoms that impair QOL despite optimal PAH therapy; however, PC awareness and utilization for PAH providers is low. Opportunities may exist to integrate PC into care for PAH patients.

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by severe remodeling of the pulmonary artery resulting in increased pulmonary artery pressure and right ventricular hypertrophy and, ultimately, failure. Bone marrow–derived progenitor cells play a critical role in vascular homeostasis and have been shown to be involved in the pathogenesis of PAH. A proliferation of c‐Kit+ hematopoietic progenitors and mast cells has been noted in the remodeled vessels in PAH. Imatinib, a tyrosine kinase inhibitor that targets c‐Kit, has been shown to be beneficial for patients with PAH. Here we hypothesize that the clinical benefit of imatinib in PAH could be related to c‐Kit inhibition of progenitor cell mobilization and maturation into mast cells. As a corollary to the phase 3 study using imatinib in PAH, blood samples were collected from 12 patients prior to starting study drug (baseline) and while on treatment at weeks 4 and 24. Eight were randomized to imatinib and 4 to placebo. Circulating c‐Kit+ and CD34+ CD133+ hematopoietic progenitors as well as biomarkers of mast cell numbers and activation were measured. Circulating CD34+ CD133+ and c‐Kit+ progenitor cells as well as c‐Kit+/CD34+ CD133+ decreased with imatinib therapy (all P < 0.05). In addition, total tryptase, a marker of mast cell load, dropped with imatinib therapy (P = 0.02) and was related to pulmonary vascular resistance (R = 0.7, P = 0.02). The findings support c‐Kit inhibition as a potential mechanism of action of imatinib in PAH and suggest that tryptase is a potential biomarker of response to therapy.

Purpose: Among phosphodiesterase type 5 inhibitors, tadalafil offers clinicians a once-daily alternative to 3 times daily sildenafil for the treatment of pulmonary arterial hypertension (PAH). This study assessed the safety and patient satisfaction with conversion from sildenafil to tadalafil. Methods: In this multicenter, prospective, 6-month study, patients with PAH were instructed to take their last dose of sildenafil in the evening and initiate tadalafil 40 mg/d the next morning. Patients completed the Treatment Satisfaction Questionnaire for Medication at baseline and 30, 90, and 180 days after transition to assess PAH symptoms and patient satisfaction. Safety was assessed on the basis of recorded adverse events (AEs). Results: Of the 35 patients who met the study criteria, 56% were receiving ≥2 PAH therapies. At the time of transition, the sildenafil dose ranged from 40 to 300 mg/d, with 20% of the patients on >20 mg of sildenafil 3 times daily. Transition to tadalafil was generally well tolerated, and the incidence of common AEs, except for myalgia, appeared to decrease over time on tadalafil therapy. Five (14%) patients switched back to sildenafil. A greater percentage of patients were satisfied than were dissatisfied after conversion to tadalafil (55% vs 19% at 90 days), while 26% felt about the same degree of satisfaction. Conversion to tadalafil resulted in significant improvement in patient ratings of therapy convenience. Conclusions: Transition of patients from sildenafil to tadalafil was usually well tolerated, with improved convenience and may enhance treatment satisfaction.

Pulmonary arterial hypertension (PAH) is characterized by progressive increases in pulmonary vascular resistance, leading to right heart failure and death. Guidelines recommend customization of treatment, necessitating the development of effective strategies for transitioning patients among treatments. In this study, we characterized our experience with patient transitions from parenteral prostacyclin to inhaled iloprost. We retrospectively assessed records from 11 centers of 37 consecutive patients with PAH aged ≥ 18 years who were treated with intravenous (IV) or subcutaneous (SC) prostacyclin analogues and transitioned to inhaled iloprost. The transition period began on the first day of inhaled iloprost with the intent of discontinuing parenteral prostacyclin and ended on the first day on inhaled iloprost free of parenteral prostacyclin. Persistence was defined as the absence of (1) parenteral prostacyclin while remaining on inhaled iloprost during post‐transition Days 1–90 and (2) no reinitiation of parenteral prostacyclin during post‐transition Days 90–365. All patients were clinically stable before transitioning to inhaled iloprost. The mean age was 46.5 years, 70.3% were female, 51.4% had idiopathic PAH, and 43.0% were in New York Heart Association Functional Class III. Among patients with an overlapping transition, the mean transition period was 10.5 days. A transition dosing algorithm was used in 10 patients (27.0%). At one year, 78.4% of the patients remained persistent on inhaled iloprost and 81.1% were free of clinical worsening. In selected patients on background oral PAH therapy, transitioning from parenteral prostacyclin to inhaled iloprost appears safe and feasible and is associated with long‐term success. Further study is needed to define the optimal patient selection criteria and transition algorithm.

Background— Although right ventricular (RV) dysfunction is a major determinant of outcome in patients with pulmonary hypertension (PH), the optimal measure of RV function is poorly defined. We hypothesized that RV strain measured by speckle-tracking echocardiography predicts outcome in PH over a broad range of pulmonary pressures. Methods and Results— Prospective peak RV longitudinal systolic strain measurement was performed on 575 patients (mean age, 56±18 years; 63% women) referred for echocardiography for known or suspected PH. Survival status was assessed over a median of 16.5 (interquartile range, 7.6–20.0) months. There were 406 patients with PH (71%) (74% group 1, 14% group 3, and 12% group 4) and 169 patients without evidence of PH (29%). Among patients with PH, 46% were World Health Organization functional class III–IV. The mean RV strain was −21.2±6.7% for all patients. RV strain declined with worse functional class, shorter 6-minute walk distances, higher N-terminal pro-B-type natriuretic peptide levels, and the presence of right heart failure. RV strain predicted outcome across pulmonary pressures and groups of PH. Eighteen-month survival was 92%, 88%, 85%, and 71% according to RV strain quartile ( P <0.001), with a 1.46 higher risk of death (95% confidence interval, 1.05–2.12) per 6.7% decline in RV strain. RV strain predicted survival when adjusted for pulmonary pressure, pulmonary vascular resistance, and right atrial pressure and provided incremental prognostic value over conventional clinical and echocardiographic variables. Conclusions— Quantitative assessment of RV free-wall systolic strain is feasible and is a powerful predictor of the clinical outcome of patients with known or suspected PH.

Background— Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling and right heart failure. The right (RV) and left ventricles (LV) do not function in isolation, sharing a common pericardial sac and interventricular septum. We sought to define the clinical and prognostic significance of ventricular interdependence in PAH and its association with LV filling patterns through speckle-tracking strain echocardiography. Methods and Results— Echocardiography was performed in 71 adults with a new diagnosis of PAH. To analyze LV and RV function separately, we measured peak systolic longitudinal and circumferential strain of the LV and RV. Survival was assessed >2 years. Patients had dilated right-sided chambers (right atrial volume index, 44±19 mL/m 2 ; RV end-diastolic area, 34±9 cm 2 ), and reduced RV function (RV fractional area change, 28±12%). Speckle-tracking echocardiography revealed significant reductions in RV free wall peak systolic strain (−15±3%). Despite normal LV size and normal conventional measures of LV systolic function (end-diastolic dimension, 42±6 mm; ejection fraction, 65±8%; cardiac index, 2.6±0.8 L/min per m 2 ), patients had reduced LV free wall systolic strain (−15±3%). Decreased LV free wall systolic strain was associated with a delayed relaxation mitral inflow Doppler pattern, P =0.0002. During 2-year follow-up, 19 patients (27%) died. LV strain was associated with increased mortality (unadjusted hazard ratio, 2.40 per 5% decrease in LV free wall strain, 1.22–4.68), which remained significant when adjusted for age, sex, World Health Organization functional class, and PAH pathogenesis (hazard ratio, 3.11, 1.38–7.20). Conclusions— The pressure loading in PAH results in geometric alterations and functional decline of the RV, with marked reduction in RV systolic strain. Despite preservation of LV ejection fraction, LV systolic strain was also reduced and associated with early mortality, highlighting the significance of ventricular interdependence in PAH.