Kubba, Saad

Background: Normative changes in right ventricular (RV) structure and function have not been characterized in the context of treatment-associated functional recovery (RV functional recovery [RVFnRec]). The aim of this study is to assess the clinical relevance of a proposed RVFnRec definition. Methods: We evaluated 63 incident patients with pulmonary arterial hypertension by right heart catheterization and cardiac magnetic resonance imaging at diagnosis and cardiac magnetic resonance imaging and invasive cardiopulmonary exercise testing following treatment (≈11 months). Sex, age, ethnicity matched healthy control subjects (n=62) with 1-time cardiac magnetic resonance imaging and noninvasive cardiopulmonary exercise testing were recruited from the PVDOMICS (Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics) project. We examined therapeutic cardiac magnetic resonance imaging changes relative to the evidence-based peak oxygen consumption (VO 2peak )>15 mL/(kg·min) to define RVFnRec by receiver operating curve analysis. Afterload was measured as mean pulmonary artery pressure, resistance, compliance, and elastance. Results: A drop in RV end-diastolic volume of −15 mL best defined RVFnRec (area under the curve, 0.87; P =0.0001) and neared upper 95% CI RV end-diastolic volume of controls. This cutoff was met by 22 out of 63 (35%) patients which was reinforced by freedom from clinical worsening, RVFnRec 1 out of 21 (5%) versus no RVFnRec 17 out of 42, 40% (log-rank P =0.006). A therapy-associated increase of 0.8 mL/mm Hg in compliance had the best predictive value of RVFnRec (area under the curve, 0.76; [95% CI, 0.64–0.88]; P =0.001). RVFnRec patients had greater increases in stroke volume, and cardiac output at exercise. Conclusions: RVFnRec defined by RV end-diastolic volume therapeutic decrease of −15 mL predicts exercise capacity, freedom from clinical worsening, and nears normalization. A therapeutic improvement of compliance is superior to other measures of afterload in predicting RVFnRec. RVFnRec is also associated with increased RV output reserve at exercise.

A 41-year-old female with hyperlipidemia presented with typical exertional angina, dyspnea, and pre-syncope of 6 months duration. Physical examination was unremarkable. ECG showed low voltage QRS (Figure A), and Chest CTA was negative for obstructive-CAD, pulmonary emboli, aortic, and lung disease. Cardiac MRI was negative for myocarditis/pericarditis . Resting TTE was unremarkable with normal systolic and diastolic function. NT-Pro BNP, hs-CRP, serum/ urine protein electrophoresis, and free light chains ratio were normal. Regadenoson PET myocardial perfusion test showed a medium-sized area of stress-induced ischemia in mid/apical segments (Figure B) . Resting right heart Cath showed mean RA pressure (9mmHg) and RVEDP (10mmHg), mean PA pressure (19mmHg), and PCWP (15mmHg) with large v-waves, PCWP increased to 28mmHg with limited supine bike exercise, diagnostic of HFpEF (Figure C) . Angiography showed normal coronary arteries while coronary reactivity testing was diagnostic of severe epicardial and microvascular endothelial dysfunction (60% mid/distal LAD constriction and 19% decreased blood flow in response to intracoronary (IC) acetylcholine), and endothelial-independent microvascular dysfunction (coronary flow reserve 2.4 in response to IC adenosine), diagnostic of HFpEF due to coronary endothelial and microvascular disease (Figure D) . The patient’s symptoms improved at 2 weeks follow-up after initiation of furosemide, diltiazem, isosorbide mononitrate, and atorvastatin.