Pulmonary hypertension (PH) is common among patients with myeloproliferative neoplasm (MPN) and is linked to left ventricular (LV) hypertrophy and diastolic dysfunction, according to study results published in the Journal of the American Society of Echocardiography.
In this retrospective cohort study using consecutive patients with MPN who underwent transthoracic echocardiography between February 2011 and October 2017 (N=301), researchers used established cutoffs for PH (≥35 mm Hg) and advanced PH (≥50 mm Hg) and assessed LV and right ventricular (RV) performance via conventional indices. For patients with multiple echocardiographic examinations, they analyzed the initial examination that demonstrated impaired RV function to assess prognostic impact. Investigators collected data on demographics, cardiac indices, symptoms, medications, and mortality via electronic medical record review.
Echocardiographic data analysis showed that 56% of patients with MPN had PH, and PH was strongly associated with adverse LV remodeling, particularly in patients with advanced PH. There was a near 20% increment in LV mass in patients with advanced PH vs patients without advanced PH (104±33 g/m² vs 89±27 g/m²; P =.002). The prevalence of LV diastolic dysfunction was 1.4-fold higher in patients with PH (72% vs 51%; P =.001). In all multivariate analyses, PH was associated with increased LV mass (odds ratio 1.02/10 g/m²; 95% CI, 1.01-1.03; P =.004). After a mean follow-up of 2.6±2.1 years to assess PH and RV remodeling as risk factors for mortality, all-cause mortality was 27% (n=80). Patients with higher PH grade had higher mortality risk (hazard ratio 2.2; 95% CI, 1.5-3.3; P <.001).
Limitations of this study include possible differences in MPN course; echocardiography was performed at a single time point. Clinical factors likely influenced the sample, as symptomatic patients are more likely to be referred for echocardiography; therefore, the results may not generalize to prevalence of PH in unselected MPN cohorts. In addition, researchers used linear dimensions to calculate LV volumes, and this method may have limitations in PH because of asymmetric LV distortion. They did not test reproducibility for the full range of conventional echocardiographic indices included in this study.
The evaluation of patients with MPN should emphasize the high risk for PH and RV dysfunction with regard to symptom and risk management.
The researchers concluded, “Although it is likely that the prognostic implications conferred by PH would be expected in other at-risk populations, it should be noted that prevalence of PH in our cohort (56%) and in prior smaller scale MPN studies (42%-48%) was >2-fold than that reported in other noncancer populations with conditions predisposing to PH, such as individuals with systemic hypertension (20%), highlighting substantial magnitude to which MPN confers risk for PH.”
Kim J, Krichevsky S, Xie L. Incremental utility of right ventricular dysfunction in patients with myeloproliferative neoplasm-associated pulmonary hypertension [published online October 3, 2019]. J Am Soc Echocardiogr. doi: 10.1016/j.echo.2019.07.010