Left atrial (LA) size and function is recognized as a cumulative index of pulmonary capillary wedge pressure (PCWP) and an index of left heart disease (LHD). While anticipated that LA features contribute to LHD-associated pulmonary hypertension (PH), we hypothesized that LA abnormalities (LAA) may exist in other WSPH groups. Therefore, we examined LA structure and function in the PVDOMICS cohorts. PVDOMICS enrolled 1097 total subjects with PH (mPA > 25 mmHg) and at-risk disease comparators (mPA<25 mmHg) for each of the WSPH groups. Patients with WSPH Groups 1, 3, 4, and 5 [non-Group 2] (n=618) were younger (56.2 ± 14.5 vs 60.1 ± 12.7 yrs, p<.02) and had less hypertension (38.6% vs 51.5 %, p<.02) than their non-Group 2 comparators (n=204). They also had less hypertension, diabetes, and a lower BMI than WSPH Group 2 (n=145), whereas WSPH Group 2 and its comparator Group 2 (n=130) were similar. LA area by echo was greater in WSPH Group 2 compared to non-Group 2 (22.8 ± 6.6 vs 16.9 ± 5.0 cm 2 , p<.02), in the comparator Group 2 vs. non-Group 2 comparators (22.7 ± 7.9 vs 16.4 ± 4.7 cm 2 , p<.02) but similar between WSPH group 2 and its comparator. MRI LA ejection fraction was lowest in Group 2 (33.2 ± 17.7%) and comparator Group 2 (38.9 ±16.7%, p=ns), significantly lower than WSPH non-Group 2 (45.9 ±14.7%, p<.02) which was lower than comparator non-Group 2 (50.9 14.6%, p<.02) which was lower than normal controls (n=96) (58.4 ±1.7%, p<.02). At right heart catheterization, whereas mPA pressures were similar between WSPH non-Group 2 and Group 2, resting PCW (11.1± 5.3 vs 20.3 5.6 mm Hg, p<0.02) was lower in WSPH non-Group 2 , PVR was higher (5.5[3.3, 8.7] vs. 3.7[7.2, 5.7] WU, p<0.02), and cardiac output was higher (5.4 ± 1.9 vs. 4.9 ± 1.6 L/min, p<0.02). Following a fluid challenge, PCW remained lower (14.9 ± 5.8 vs 20.7 ± 4.5 mm Hg, p<0.02) and PVR higher (5.2[3.1, 7.8] vs. 3.2[2.3, 5.5] WU, p<0.02). PCW and PVR at rest were lower in the comparator non-Group 2 vs WSPH non-Group 2 (8.9 ± 4.1 vs 11.1± 5.3 mm Hg, p<.02) and 1.7[1.2, 2.3] vs 5.5[3.3, 8.7] WU, p<.02. Thus, while LAA are most notable in WSPH and comparator Group 2’s, LAA differ between WSPH non-Group 2 and its non-Group 2 comparators. The role of LAA as predictors of PH outcomes remains to be determined.
Abstract 15029: Atrial Arrhythmias and Pulmonary Hypertension Across Wsph Groups
Introduction: Previous reports have shown that atrial and ventricular arrhythmias (VA) are common in all forms of pulmonary hypertension (PH) with prevalence of supraventricular arrhythmias ranging from 13-25% and VA 27%. Arrhythmias are also associated with clinical worsening events. Reports have limited numbers of patients with a variety of forms of PH and limited data comparing the prevalence of atrial arrhythmias across WSPH groups and whether advancing age, WHO FC, echocardiographic, exercise capacity and hemodynamic patterns are associated with a higher prevalence of atrial arrhythmias. Methods: As part of the PVDOMICS program, we enrolled 1195 PH participants, controls and PH comparators and prospectively collected electrocardiograms (ECGs) at enrollment for 1147 of them. Comparisons across participants with and without atrial fibrillation/atrial flutter (afib/flutter) used analysis of variance (ANOVA) or Kruskal-Wallis test in continuous variables based on distribution with statistics presented as mean + SD or median [P25, P75] respectively. Pearson’s chi-square test was used for categorical variables. Results: Of 732 PH participants (467F) who had ECGs available at baseline, 527 (72.0%) were in normal sinus rhythm and 62 had afib/flutter (8.5%). Afib/flutter participants were older (75 + 8 vs 57 + 14 years; p<0.001), most commonly in WSPH group 2 (28.1%) vs. WSPH 1 (3.3%), WSPH 3(6.5%) and WSPH group 4 (3.7%), had predominantly WHO FC II/III symptoms (89.5%), higher RAP (12.6 + 5 vs.7.8 + 5mmHg; p<0.001) and PCWPm (17.8 + 5.8 vs. 12.3 + 6.2mmHg; p<0.001) and lower CO (4.3+ 1.5 vs. 5.2 +1.8L/min;p<0.001). Participants with afib/flutter had lower 6MWD 277 + 117 vs.356 + 134meters (p<0.001) than PH participants without. Echocardiography demonstrated increase in LA volume index (mL/m2), RA volume (mL) and tricuspid regurgitation severity with reduced TAPSE and LVEF (54 + 10 vs. 61 + 10%;p<0.001). ProBNP was higher in afib/flutter participants 2029 [1073, 2964] vs.268 [100, 1074]pg/ml; P<0.001) Conclusions: In this analysis of atrial arrhythmias in a large cohort of PH participants across all WSPH groups, afib/flutter was present most often in older WSPH group 2 patients who demonstrated clinical and hemodynamic features of worse heart failure.
Comprehensive Diagnostic Evaluation of Cardiovascular Physiology in Patients With Pulmonary Vascular Disease
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.