Frantz, Robert P

Abstract Rationale Prostacyclin-associated leg pain is a potentially debilitating adverse effect of prostacyclin therapy for patients with pulmonary arterial hypertension (PAH). However, to our knowledge, this entity has not been systematically studied. Objectives To characterize the clinical features and metabolic risk factors for prostacyclin-associated leg pain. Methods At one academic medical center, we assembled and analyzed a case series of patients with PAH and prostacyclin-associated leg pain. Measurements and Main Results Over a period of 2 years, we identified 11 patients with PAH and prostacyclin-associated leg pain who agreed to participate in this study. Subjects underwent a standardized clinical evaluation, electrodiagnostic assessment, and serologic screen for metabolic causes of peripheral neuropathy. All 11 patients were female; their mean (SD) age was 50 (±9) years; their median (interquartile range) PAH duration was 56 (20–96) months; and their prostacyclin therapy duration was a median (interquartile range) of 20 (14–36) months. All patients reported leg pain beginning soon after prostacyclin initiation and varying with dose. All described a neuropathic pain in a symmetric, distal, stocking distribution. Neurologic examination revealed a sensory, small-fiber, predominantly peripheral neuropathy in seven (78%) patients. Results of autonomic reflex testing and thermoregulatory sweat testing were abnormal in 82% and 90% of patients, respectively, suggesting small-fiber neuropathy. Serologic evaluation identified a new, previously unrecognized contributor to neuropathy in eight (73%) patients, including vitamin B12 deficiency in six (55%), uncompensated hypothyroidism in three (27%), and diabetes mellitus in one (9%). Conclusions Chronic prostacyclin-associated leg pain is associated with a small-fiber neuropathy. Treatable metabolic contributors (vitamin B12 deficiency, thyroid dysfunction, or diabetes) appear to be common possible “second hits” that may be underrecognized. We recommend screening for possible metabolic contributors in patients who have otherwise unexplained leg pain in the setting of PAH and current or anticipated prostacyclin therapy.

Background Current mortality data for pulmonary arterial hypertension (PAH) in the United States are based on registries that enrolled patients prior to 2010. We sought to determine mortality in PAH in the modern era using the PHAR (Pulmonary Hypertension Association Registry). Methods and Results We identified all adult patients with PAH enrolled in the PHAR between September 2015 and September 2020 (N=935). We used Kaplan‐Meier survival analysis and Cox proportional hazards models to assess mortality at 1, 2, and 3 years. Patients were stratified based on disease severity by 3 validated risk scores. In treatment‐naïve patients, we compared survival based on initial treatment strategy. The median age was 56 years (44–68 years), and 76% were women. Of the 935 patients, 483 (52%) were ≤6 months from PAH diagnosis. There were 121 deaths (12.9%) during a median follow‐up time of 489 days (281–812 days). The 1‐, 2‐, and 3‐year mortality was 8% (95% CI, 6%–10%), 16% (95% CI, 13%–19%), and 21% (95% CI, 17%–25%), respectively. When stratified into low‐, intermediate‐, and high‐risk PAH, the mortality at 1, 2, and 3 years was 1%, 4% to 6%, and 7% to 11% for low risk; 7% to 8%, 11% to 16%, and 18% to 20% for intermediate risk; and 12% to 19%, 22% to 38%, and 28% to 55% for high risk, respectively. In treatment‐naïve patients, initial combination therapy was associated with better 1‐year survival (adjusted hazard ratio, 0.43 [95% CI, 0.19–0.95]; P =0.037). Conclusions Mortality in the intermediate‐ and high‐risk patients with PAH remains unacceptably high in the PHAR, suggesting the importance for early diagnosis, aggressive use of available therapies, and the need for better therapeutics.

Background: Invasive hemodynamic evaluation through right heart catheterization plays an essential role in the diagnosis, categorization, and risk stratification of patients with pulmonary hypertension. Methods: Subjects enrolled in the PVDOMICS (Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics) program undergo an extensive invasive hemodynamic evaluation that includes repeated measurements at rest and during several provocative physiological challenges. It is a National Institutes of Health/National Heart, Lung, and Blood Institute initiative to reclassify pulmonary hypertension groups based on clustered phenotypic and phenomic characteristics. At a subset of centers, participants also undergo an invasive cardiopulmonary exercise test to assess changes in hemodynamics and gas exchange during exercise. Conclusions: When coupled with other physiological testing and blood -omic analyses involved in the PVDOMICS study, the comprehensive right heart catheterization protocol described here holds promise to clarify the diagnosis and clustering of pulmonary hypertension patients into cohorts beyond the traditional 5 World Symposium on Pulmonary Hypertension groups. This article will describe the methods applied for invasive hemodynamic characterization in the PVDOMICS program. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02980887.

Background The presence of a durable left ventricular assist device ( LVAD ) is associated with increased risk of vasoplegia in the early postoperative period following heart transplantation ( HT ). However, preoperative predictors of vasoplegia and its impact on survival after HT are unknown. We sought to examine predictors and outcomes of patients who develop vasoplegia after HT following bridging therapy with an LVAD . Methods and Results We identified 94 patients who underwent HT after bridging with continuous‐flow LVAD from 2008 to 2018 at a single institution. Vasoplegia was defined as persistent low vascular resistance requiring ≥2 intravenous vasopressors within 48 hours after HT for >24 hours to maintain mean arterial pressure >70 mm Hg. Overall, 44 patients (46.8%) developed vasoplegia after HT . Patients with and without vasoplegia had similar preoperative LVAD , echocardiographic, and hemodynamic parameters. Patients with vasoplegia were significantly older; had longer LVAD support, higher preoperative creatinine, longer cardiopulmonary bypass time, and higher Charlson comorbidity index; and more often underwent combined organ transplantation. In a multivariate logistic regression model, older age (odds ratio: 1.08 per year; P =0.010), longer LVAD support (odds ratio: 1.06 per month; P =0.007), higher creatinine (odds ratio: 3.9 per 1 mg/dL; P =0.039), and longer cardiopulmonary bypass time (odds ratio: 1.83 per hour; P =0.044) were independent predictors of vasoplegia. After mean follow‐up of 4.0 years after HT , vasoplegia was associated with increased risk of all‐cause mortality (hazard ratio: 5.20; 95% CI, 1.71–19.28; P =0.003). Conclusions Older age, longer LVAD support, impaired renal function, and prolonged intraoperative CPB time are independent predictors of vasoplegia in patients undergoing HT after LVAD bridging. Vasoplegia is associated with worse prognosis; therefore, detailed assessment of these predictors can be clinically important.

Adherence to therapy for pulmonary arterial hypertension is essential to optimize patient outcomes, but data on real‐world adherence to different pulmonary arterial hypertension drug classes are limited. This retrospective database analysis evaluated relationships between adherence, hospitalization, and healthcare costs in pulmonary arterial hypertension patients treated with endothelin receptor antagonists or phosphodiesterase type‐5 inhibitors. From the IQVIA Adjudicated Health Plan Database, patients with pulmonary arterial hypertension were identified based on diagnostic codes and prescriptions for endothelin receptor antagonists (ambrisentan, bosentan, macitentan) or phosphodiesterase type‐5 inhibitors (sildenafil, tadalafil) approved for pulmonary arterial hypertension. Patients were assigned to the class of their most recently initiated (index) pulmonary arterial hypertension therapy between 1 January 2009 and 30 June 2015. Medication adherence was measured by proportion of days covered; patients with proportion of days covered ≥80% were considered adherent. The proportion of adherent patients was higher for endothelin receptor antagonists (571/755; 75.6%) than for phosphodiesterase type‐5 inhibitors (970/1578; 61.5%; P < 0.0001). In both groups, hospitalizations declined as proportion of days covered increased. Among adherent patients, those on endothelin receptor antagonists had a significantly lower hospitalization rate than those on phosphodiesterase type‐5 inhibitors (23.1% versus 28.5%, P = 0. 0218), fewer hospitalizations (mean (standard deviation) 0.4 (0.8) versus 0.5 (0.9); P = 0.02), and mean hospitalization costs during the six‐month post‐index ($9510 versus $15,726, P = 0.0318). Increasing adherence reduced hospitalization risk more for endothelin receptor antagonists than for phosphodiesterase type‐5 inhibitors (hazard ratio 0.176 versus 0.549, P = 0.001). Rates and numbers of rehospitalizations within 30 days post‐discharge were similar between groups. Mean total costs were higher with endothelin receptor antagonists than phosphodiesterase type‐5 inhibitors in all patients ($91,328 versus $72,401, P = 0.0003) and in adherent patients ($88,867 versus $56,300, P < 0.0001), driven by higher drug costs.

BackgroundThe DelIVery for Pulmonary Arterial Hypertension clinical trial was a multi‐center, prospective, single arm, Investigational Device Exemption study utilizing a fully implantable, programmable intravascular delivery system consisting of a pump and a catheter for intravenous treprostinil. The study met its primary endpoint and demonstrated that the intravascular delivery system significantly reduced catheter related complications at 22,000 subject‐days of follow‐up compared with a predefined objective performance criterion. Here we summarize the results obtained during a 6.4‐year follow‐up period.MethodsThroughout study follow‐up, participants had clinic visits and medication refills at least every 12 weeks (dependent on the subjects’ dose). All adverse events and intravascular delivery system complications were evaluated and recorded.ResultsSixty pulmonary arterial hypertension subjects were followed post device implantation for approximately 282 patient‐years (range 87 days to 6.4 years). Of the 60 subjects, 14 died (1 related to intravascular delivery system pump failure), 2 withdrew after lung transplants, and 2 withdrew due to pump pocket infection. No catheter‐related bloodstream infections, catheter thrombosis or occlusions, or catheter kinks occurred through 282 patient‐years. Two participants had adverse events of abdominal pain, rash, due to subcutaneous treprostinil “leaks” after one catheter puncture and one catheter laceration during pump refill and replacement, respectively. Eight pump failure events occurred: seven pump motor stalls and one early replacement (faulty battery).ConclusionDelivery of treprostinil with an intravascular delivery system is a safe alternative to an external delivery system, while providing enhanced life experiences. To preserve the risk–benefit ratio, treatment at specialized pulmonary arterial hypertension centers is recommended until training is disseminated at other sites.

Background Diastolic pulmonary gradient ( DPG ) was proposed as a better marker of pulmonary vascular remodeling compared with pulmonary vascular resistance ( PVR ) and transpulmonary gradient ( TPG ). The prognostic significance of DPG in patients requiring a left ventricular assist device ( LVAD ) remains unclear. We sought to investigate whether pre‐ LVAD DPG is a predictor of survival or right ventricular ( RV ) failure post‐ LVAD . Methods and Results We retrospectively reviewed 268 patients who underwent right heart catheterization before LVAD implantation from 2007 to 2017 and had pulmonary hypertension because of left heart disease. Patients were dichotomized using DPG ≥7 mm Hg, PVR ≥3 mm Hg, or TPG ≥12 mm Hg. The associations between these parameters and all‐cause mortality or RV failure post LVAD were assessed with Cox proportional hazards regression and Kaplan–Meier analyses. After a mean follow‐up time of 35 months, elevated DPG was associated with increased risk of RV failure (hazard ratio [ HR ]: 3.30; P =0.004, for DPG ≥7 versus DPG <7), whereas elevated PVR ( HR 1.85, P =0.13 for PVR ≥3 versus PVR <3) or TPG ( HR 1.47, P =0.35, for TPG ≥12 versus TPG <12) were not associated with the development of RV failure. Elevated DPG was not associated with mortality risk ( HR 1.16, P =0.54, for DPG ≥7 versus DPG <7), whereas elevated PVR , but not TPG , was associated with higher mortality risk ( HR 1.55; P =0.026, for PVR ≥3 versus PVR <3). Conclusions Among patients with pulmonary hypertension because of left heart disease requiring LVAD support, elevated DPG was associated with RV failure but not survival, while elevated PVR predicted mortality post LVAD implantation.

Pulmonary arterial hypertension (PAH) is a rare disease that carries a poor prognosis. For 45 years, the definition of pulmonary hypertension (PH) has been a mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg, based on expert opinion. Recent data indicate that the mortality risk starts in the mPAP range of 21–24 mmHg, which has recently been reflected in the World Symposium on PH consensus document defining PH as a mPAP > 20 mmHg. The mortality associated with these lower levels of pulmonary pressures suggests that these values reflect a more advanced disease stage than previously recognized. It is unknown whether interventions targeting patients with mPAP values in the range of 21–24 mmHg in the absence of left ventricular or hypoxic lung disease are of clinical benefit. Here we present historical perspective on the hemodynamic definition of PH, discuss recent epidemiologic data, and outline obstacles to enrolling and evaluating response to therapy in mild PAH patients, as well as potentially useful study designs.

Background Left ventricular (LV) hemodynamic assessment has been sparsely performed in patients supported on continuous‐flow LV assist devices (cf LVADs ). Insight into dynamic changes of left heart parameters during ramp studies may improve LV assist device optimization and evaluate pathology. Methods and Results To complement right heart catheterization, a novel technique for left heart catheterization in patients with a cf LVAD was developed. Patients implanted with cf LVAD s underwent hemodynamic ramp left heart catheterization and right heart catheterization with transthoracic echocardiography. Continuous aortic and LV pressures were measured along with right atrial, pulmonary artery, and pulmonary capillary wedge pressures. A novel index, the transaortic gradient ( TAG ) was established. Thirty eight patients with cf LVADs were evaluated at a median of 446 days (interquartile range, 183–742) after device implant. During left heart catheterization performed for hemodynamic optimization, drop‐in LV end‐diastolic pressure and pulmonary capillary wedge pressure were associated with a rise in TAG . A range was identified for TAG (20–40 mm Hg) as providing the most optimal level of hemodynamic offloading. Pathologic states deviated from normal responses to ramp. LV assist device thrombosis was associated with an inability to increase in TAG during speed ramp. Significant aortic insufficiency was associated with a marked increase in LV end‐diastolic pressure despite a concomitant decrease in pulmonary capillary wedge pressure with increasing LV assist device speeds. Conclusions Inclusion of left heart catheterization to a typical right heart catheterization LV assist device ramp protocol imparted unique insights to optimize cf LVAD speeds in different clinical scenarios. A novel index, the TAG was defined and provided additional resolution to optimized offloading.