Erratum: Relationship between Right Ventricular Longitudinal Strain, Invasive Hemodynamics, and Functional Assessment in Pulmonary Arterial Hypertension

The authors have decided to remove one of the authors, Serpil C. Erzurum, MD, who was cited as the 5th author on the original manuscript.

Relationship between Right Ventricular Longitudinal Strain, Invasive Hemodynamics, and Functional Assessment in Pulmonary Arterial Hypertension

BACKGROUND AND OBJECTIVES: Right ventricular longitudinal strain (RVLS) is a new parameter of RV function. We evaluated the relationship of RVLS by speckle-tracking echocardiography with functional and invasive parameters in pulmonary arterial hypertension (PAH) patients. SUBJECTS AND METHODS: Thirty four patients with World Health Organization group 1 PAH (29 females, mean age 45+/-13 years old). RVLS were analyzed with velocity vector imaging. RESULTS: Patients with advanced symptoms {New York Heart Association (NYHA) functional class III/IV} had impaired RVLS in global RV (RVLS(global), -17+/-5 vs. -12+/-3%, p<0.01) and RV free wall (RVLS(FW), -19+/-5 vs. -14+/-4%, p<0.01 to NYHA class I/II). Baseline RVLS(global) and RVLS(FW) showed significant correlation with 6-minute walking distance (r=-0.54 and r=-0.57, p<0.01 respectively) and logarithmic transformation of brain natriuretic peptide concentration (r=0.65 and r=0.65, p<0.01, respectively). These revealed significant correlations with cardiac index (r=-0.50 and r=-0.47, p<0.01, respectively) and pulmonary vascular resistance (PVR, r=0.45 and r=0.45, p=0.01, respectively). During a median follow-up of 33 months, 25 patients (74%) had follow-up examinations. Mean pulmonary arterial pressure (mPAP, 54+/-13 to 46+/-16 mmHg, p=0.03) and PVR (11+/-5 to 6+/-2 wood units, p<0.01) were significantly decreased with pulmonary vasodilator treatment. RVLS(global) (-12+/-5 to -16+/-5%, p<0.01) and RVLS(FW) (-14+/-5 to -18+/-5%, p<0.01) were significantly improved. The decrease of mPAP was significantly correlated with improvement of RVLS(global) (r=0.45, p<0.01) and RVLS(FW) (r=0.43, p<0.01). The PVR change demonstrated significant correlation with improvement of RVLS(global) (r=0.40, p<0.01). CONCLUSION: RVLS correlates with functional and invasive hemodynamic parameters in PAH patients. Decrease of mPAP and PVR as a result of treatment was associated with improvement of RVLS.

Validation of Global Longitudinal Strain and Strain Rate as Reliable Markers of Right Ventricular Dysfunction: Comparison with Cardiac Magnetic Resonance and Outcome

BACKGROUND: Right ventricular (RV) dysfunction in ischemic cardiomyopathy (ICM) is associated with poor prognosis, but RV assessment by conventional echocardiography remains difficult. We sought to validate RV global longitudinal strain (RVGLS) and global longitudinal strain rate (RVGLSR) against cardiac magnetic resonance (CMR) and outcome in ICM. METHODS: In 57 patients (43 men, 64 +/- 12 years) with ICM who underwent conventional and strain echocardiography and CMR, RVGLS and RVGLSR were measured off-line. RV dysfunction was determined by CMR [RV ejection fraction (RVEF) < 50%]. Patients were followed over 15 +/- 9 months for a composite of death and hospitalization for worsening heart failure. RESULTS: RVGLS showed significant correlations with CMR RVEF (r = -0.797, p < 0.01), RV fractional area change (RVFAC, r = -0.530, p < 0.01), and tricuspid annular plane systolic excursion (TAPSE, r = -0.547, p < 0.01). RVGLSR showed significant correlations between CMR RVEF (r = -0.668, p < 0.01), RVFAC (r = -0.394, p < 0.01), and TAPSE (r = -0.435, p < 0.01). RVGLS and RVGLSR showed significant correlations with pulmonary vascular resistance (r = 0.527 and r = 0.500, p < 0.01, respectively). The best cutoff value of RVGLS for detection of RV dysfunction was -15.4% [areas under the curve (AUC) = 0.955, p < 0.01] with a sensitivity of 81% and specificity 95%. The best cutoff value for RVGLSR was -0.94 s-1 (AUC = 0.871, p < 0.01), sensitivity 72%, specificity 86%. During follow-up, there were 12 adverse events. In Cox-proportional hazard regression analysis, impaired RVGLS [hazard ratio (HR) = 5.46, p = 0.030] and impaired RVGLSR (HR = 3.95, p = 0.044) were associated with adverse clinical outcome. CONCLUSION: Compared with conventional echocardiographic parameters, RVGLS and RVGLSR correlate better with CMR RVEF and outcome.