Pulmonary hypertension is a common respiratory disorder in dogs and can be caused by various disorders with different pathophysiologic mechanisms. In clinical practice, the most common causes of pulmonary hypertension include left-sided heart disease and pulmonary arterial hypertension associated with respiratory disease and/or hypoxemia (RD/H). Despite the seemingly high prevalence of RD/H-associated pulmonary hypertension, little is known about its clinical presentation, diagnostic characteristics, prognostic variables, therapeutic responsiveness, and/or long-term outcome.
This retrospective study evaluated patients that had RD/H-associated pulmonary hypertension documented on echocardiogram. The mechanism of each patient’s respiratory disease was characterized based on available diagnostic testing. The population was diverse and included both obstructive and restrictive disease processes.
The authors suggested a correlation between the severity of estimated pulmonary arterial pressures and patient outcome. Furthermore, intervention with phosphodiesterase-5 (PDE5) inhibitors was demonstrated to improve survival time. Although this information is preliminary and represents cumulative information of a diverse population, it shows that patients with RD/H-associated pulmonary hypertension could benefit from PDE5 inhibitors and that echocardiogram could potentially provide prognostic information.
This study provides a basis for additional studies. It demonstrates the variability in associated underlying etiologies and can help guide clinicians in identification of patients at risk for pulmonary hypertension. Additional studies evaluating therapy in subset groups will be necessary to optimize therapy and establish a better understanding of long-term outcome and progression.