Pulmonary Hypertension May Be a Relevant Comorbidity in Patients with Myelodysplastic Syndromes

Pulmonary hypertension (PH) is characterized by elevated pulmonary arterial pressure and increased pulmonary vascular resistance, leading to right-sided heart failure and death. PH is defined as an increase in mean pulmonary arterial pressure (mPAP) ≥25 mmHg at rest. PAP values can be non-invasively estimated by Doppler echocardiography while right heart catheterization is needed for definite diagnosis. Hematologic disorders are associated with PH but it is unknown if myelodysplastic syndromes (MDS) bear an increased risk for PH. The objective of this study was to investigate the prevalence of PH in patients with MDS.

From March 2009 to July 2011 consecutive MDS patients were recruited from the Hematology Division of the Medical University of Graz and enrolled in this PH screening program. All patients underwent Doppler echocardiography. PH was suspected if resting systolic pulmonary arterial pressure (SPAP) exceeded 40 mmHg.

Additionally six minute walk distance (6MWD), pulmonary function test (PFT), laboratory tests including N-terminal pro brain natriuretic peptide (NT-proBNP), IPSS Score and WHO functional class were determined.

Fourty four MDS patients (female:male=18:26, age 70±12 years, disease onset 5±8 years, NYHA functional class I:II:III:IV=21:16:7:0, IPSS low/intermediate-I/intermediate- II/high/unknown=16:14:8:3:3; hemoglobin: 11±2 g/dl, white blood cell count 4±3 g/l; platelet count 159±125 g/l; regular transfusions n=19; WHO Classification: RCUD/RARS/RCMD/MDS del(5q)/RAEBI/RAEB II/MDSU=2:3:21:2:6:6:4 ) were included.

Six patients had elevated SPAP (PH group, SPAP: 56±9mmHg) vs. 38 patients with normal values (SPAP 29±5mmHg). PH group were slightly older (79±9 vs. 69±11 years, p=0.53), had a decreased right ventricular function (TAPSE: 18±5mm vs. 22±4mm, p=0.05), a larger left atrium (46±5mm vs. 36±9mm measured in the parasternal long axis, p=0.005), a slightly decreased left ventricular systolic function (fractional shortening: 30±11% vs. 38±9 %, p=0.1) a significantly lower 6MWD (275±117m vs. 438±105m, p=0.01) and higher NT proBNP (4515±4732 pg/ml vs. 313±252 pg/ml, p=0.001) than patients with normal SPAP. In 4/6 PH group patients a relevant diastolic dysfunction of the left ventricle was suggested by echocardiography.

According to our data, PH is present in about 15% of MDS patients and is associated with decreased physical capacity and heart failure. This suggests that PH may be considered as a relevant comorbidity in this cohort of patients. The reason of PAP increase may be multifactorial, postcapillary factors probably playing a relevant role.

No relevant conflicts of interest to declare.