Imaging in Pulmonary Vascular Disease-Understanding Right Ventricle-Pulmonary Artery Coupling.

The right ventricle (RV) and pulmonary arterial (PA) tree are inextricably linked, continually transferring energy back and forth in a process known as RV-PA coupling. Healthy organisms maintain this relationship in optimal balance by modulating RV contractility, pulmonary vascular resistance, and compliance to sustain RV-PA coupling through life's many physiologic challenges. Early in states of adaptation to cardiovascular disease-for example, in diastolic heart failure-RV-PA coupling is maintained via a multitude of cellular and mechanical transformations. However, with disease progression, these compensatory mechanisms fail and become maladaptive, leading to the often-fatal state of "uncoupling." Noninvasive imaging modalities, including echocardiography, magnetic resonance imaging, and computed tomography, allow us deeper insight into the state of coupling for an individual patient, providing for prognostication and potential intervention before uncoupling occurs. In this review, we discuss the physiologic foundations of RV-PA coupling, elaborate on the imaging techniques to qualify and quantify it, and correlate these fundamental principles with clinical scenarios in health and disease. © 2022 American Physiological Society. Compr Physiol 12: 1-26, 2022.

Metolazone Versus Intravenous Chlorothiazide for Decompensated Heart Failure Sequential Nephron Blockade: A Retrospective Cohort Study.

BACKGROUND: Metolazone and intravenous (IV) chlorothiazide are commonly used diuretics for sequential nephron blockade (SNB) in patients with acute decompensated heart failure (ADHF). Previous studies suggest metolazone may be comparable with chlorothiazide in terms of efficacy and safety. The objective of this study was to determine whether IV chlorothiazide is superior to metolazone in increasing net urine output (UOP) of hospitalized patients with ADHF. METHODS AND RESULTS: This retrospective cohort study included hospitalized patients with ADHF and evidence of loop diuretic resistance in a tertiary academic medical center. The primary end point was the change in net 24-hour UOP in patients treated with IV chlorothiazide compared with metolazone. The relative cost of chlorothiazide doses and metolazone doses administered during SNB was a notable secondary end point. The median change in net 24-hour UOP in the IV chlorothiazide group was -1481.9 mL (interquartile range -2696.0 to -641.0 mL) and -1780.0 mL (interquartile range -3084.5 to -853.5 mL) in the metolazone group (P = .05) across 220 hospital encounters. The median cost of chlorothiazide and metolazone doses used during SNB was $360 and $4, respectively (P < .01). CONCLUSIONS: Chlorothiazide was not superior to metolazone in changing the net 24-hour UOP of patients with ADHF and loop resistance. Preferential metolazone use in SNB is a potential cost-saving measure.

Management of Pulmonary Arterial Hypertension.

PURPOSE OF REVIEW: This review focuses on the therapeutic management and individualized approach to Group 1 pulmonary arterial hypertension (PAH), utilizing Food and Drug Administration-approved PAH-specific therapies and various interventional and surgical options for PAH. RECENT FINDINGS: The paradigm for the optimal management of PAH has shifted in recent years. Upfront combination therapy with an endothelin receptor antagonist and a phosphodiesterase 5 inhibitor is now widely accepted as standard of care. In addition, there is increasing emphasis on starting prostanoids early in order to delay time to clinical worsening. However, less is known regarding which prostanoid agent to initiate and the optimum time to do so. In order to facilitate shared decision-making, there is an increasing need for decision tools based on guidelines and collective clinical experiences to navigate between pharmacologic and interventional treatments, as well as explore innovative, therapeutic pathways for PAH. SUMMARY: The management of PAH has become increasingly complex. With a growing number of PAH-specific therapies, intimate knowledge of the therapeutics and the potential barriers to adherence are integral to providing optimal care for this high-risk patient population. While current PAH-specific therapies largely mediate their effects through pulmonary vasodilation, ongoing research efforts are focused on ways to disrupt the mechanisms leading to pulmonary vascular remodeling. By targeting aberrations identified in the metabolism and proliferative state of pulmonary vascular cells, novel PAH treatment pathways may be just on the horizon.

Empowering People Living with Heart Failure.

Heart failure is a chronic disease with a multitude of different clinical manifestations. Empowering people living with heart failure requires education, support structure, understanding the needs of patients, and reimaging the care delivery systems currently offered to patients. In this article, the authors discuss practical approaches to activate and empower people with heart failure and enable patient-provider dialogue and shared decision making.

Transitioning Between Prostanoid Therapies in Pulmonary Arterial Hypertension.

Background: New oral prostacyclin therapies and prostacyclin agonists have become available for the treatment of pulmonary arterial hypertension (PAH). However, methods for transitioning between oral, inhaled, and parenteral formulations are not well-established, except in the form of case reports and case series. Collectively, these emphasize the lack of a standardized process and approach in transitioning patients between PAH prostanoid therapies. In this case series, we report our experience at an accredited Pulmonary Hypertension center in transitioning between various oral, inhaled, and parenteral prostanoids to offer additional guidance on safe transitions in therapy. Methods: All cases of prostanoid transitions at an accredited Pulmonary Hypertension center from March 2018 to September 2019 were included in this report. The transition approach for each case was developed through a review of the literature, extrapolation of available pharmacokinetic data, and collaboration between pharmacists and clinicians. Results: This case series describes the transition of 3 patients from selexipag to parenteral treprostinil; 1 patient transitioning from parenteral treprostinil to selexipag; 1 patient transitioning from oral treprostinil to parenteral treprostinil; and 1 patient transitioning from inhaled treprostinil to selexipag. Four of the 6 patients presented here were transitioned to an alternate prostanoid on account of clinical worsening, while the remaining 2 patients transitioned due to intolerance of parenteral therapy and poor medication adherence. This case series includes patients with various etiologies of PAH including idiopathic PAH, methamphetamine-associated PAH, and scleroderma-associated PAH. All patients successfully completed each transition without serious adverse events. Conclusions: With the increasing utilization and availability of prostanoids, there is a critical need for a standardized approach in transitioning safely between different formulations without compromising treatment efficacy. In this case series, we present our clinical experiences, guided by available pharmacokinetic data, in transitioning between various prostanoid formulations.