ORIGINAL ARTICLE   

Minerva Cardioangiologica 2018 October;66(5):523-7

DOI: 10.23736/S0026-4725.18.04592-9

Copyright © 2018 EDIZIONI MINERVA MEDICA

language: English

The obesity paradox: the protective effect of obesity on right ventricular function using echocardiographic strain imaging in patients with pulmonary hypertension

Hiten PATEL ¹ ✉, Suchit BHUTANI ², Sahitya POSIMREDDY ¹, Priyank SHAH ¹, Upamanyu RAMPAL ¹, Apurva GANDHI ², Rahul VASUDEV ¹, Raja PULLATT ³, Hartaj VIRK ¹, Fayez SHAMOON ¹, Mahesh BIKKINA ¹, Irvin GOLDFARB ⁴

¹ Division of Cardiology, Department of Internal Medicine, New York Medical College, Saint Joseph’s Regional Medical Center, Paterson, NJ, USA; ² Department of Internal Medicine, Abington Hospital - Jefferson Health, Abington, PA, USA; ³ Division of Cardiology, Department of Internal Medicine, Trinitas Regional Medical Center, Seton Hall University, South Orange, NJ, USA; ⁴ Division of Cardiology, Department of Internal Medicine, New York Medical College, Saint Michael’s Medical Center, Newark, NJ, USA

BACKGROUND: Obesity is associated with right ventricular (RV) dysfunction, but its effect on RV remodeling in patients with pulmonary hypertension (PHTN) has not been studied. We evaluated the effect of obesity, and its interplay with diabetes, in patients with PHTN using RV echocardiographic strain imaging.
METHODS: One hundred eighty-five patients underwent echocardiographic imaging and pulmonary artery pressure was calculated using tricuspid regurgitation jet velocity. From focused RV apical-four-chamber view, global and mid peak systolic RV free wall longitudinal strain (FWLS) was calculated using speckle-tracking software.
RESULTS: Global and mid RV FWLS in patients with PHTN (N.=84) was lower (-16.8±7 vs. 18.9±6.3, P=0.035 and -11.2±12.8 vs. -18.9±9.2, P=0.002 respectively) compared with patients without PHTN (N.=101). Among patients without PHTN, obese patients (BMI>30) had lower global and mid RV FWLS (-17.2±6.2 vs. -20.3±5.7, P=0.012 and -17.6±7.2 vs. -21.9±7.3, P=0.004), even after excluding diabetic patients (Mid RV FWLS -18.2±6.8 vs. -22.1±8, P=0.032). Among patients with PHTN, obese patients had similar RV FWLS compared with non-obese patients (P=0.46). However, on excluding diabetic patients from PHTN group, obese patients with PHTN had higher global and mid RV FWLS (-21.7±5.7 vs. -16.1±8, P=0.017 and 23.8±4.8 vs. -17±9.4, P=0.009 respectively) compared to non-obese patients which suggests a protective effect of obesity on RV function in patients with PHTN.
CONCLUSIONS: Obesity is associated with subclinical RV dysfunction as assessed by RV strain imaging, but paradoxically it may confer a protective effect on RV function once the patient develops PHTN. Future studies should evaluate the clinical impact of this paradox.

KEY WORDS: Obesity - Diabetes mellitus - Hypertension, pulmonary