Published online Aug 26, 2016. doi: 10.4330/wjc.v8.i8.472
Peer-review started: March 22, 2016
First decision: April 20, 2016
Revised: April 29, 2016
Accepted: July 11, 2016
Article in press: July 13, 2016
Published online: August 26, 2016
Processing time: 156 Days and 19.2 Hours
To find parameters from transthorathic echocardiography (TTE) including speckle-tracking (ST) analysis of the right ventricle (RV) to identify precapillary pulmonary hypertension (PH).
Forty-four patients with suspected PH undergoing right heart catheterization (RHC) were consecutively included (mean age 63.1 ± 14 years, 61% male gender). All patients underwent standardized TTE including ST analysis of the RV. Based on the subsequent TTE-derived measurements, the presence of PH was assessed: Left ventricular ejection fraction (LVEF) was calculated by Simpsons rule from 4Ch. Systolic pulmonary artery pressure (sPAP) was assessed with continuous wave Doppler of systolic tricuspid regurgitant velocity and regarded raised with values ≥ 30 mmHg as a surrogate parameter for RA pressure. A concomitantly elevated PCWP was considered a means to discriminate between the precapillary and postcapillary form of PH. PCWP was considered elevated when the E/e’ ratio was > 12 as a surrogate for LV diastolic pressure. E/e’ ratio was measured by gauging systolic and diastolic velocities of the lateral and septal mitral valve annulus using TDI mode. The results were then averaged with conventional measurement of mitral valve inflow. Furthermore, functional testing with six minutes walking distance (6MWD), ECG-RV stress signs, NT pro-BNP and other laboratory values were assessed.
PH was confirmed in 34 patients (precapillary PH, n = 15, postcapillary PH, n = 19). TTE showed significant differences in E/e’ ratio (precapillary PH: 12.3 ± 4.4, postcapillary PH: 17.3 ± 10.3, no PH: 12.1 ± 4.5, P = 0.02), LV volumes (ESV: 25.0 ± 15.0 mL, 49.9 ± 29.5 mL, 32.2 ± 13.6 mL, P = 0.027; EDV: 73.6 ± 24.0 mL, 110.6 ± 31.8 mL, 87.8 ± 33.0 mL, P = 0.021) and systolic pulmonary arterial pressure (sPAP: 61.2 ± 22.3 mmHg, 53.6 ± 20.1 mmHg, 31.2 ± 24.6 mmHg, P = 0.001). STRV analysis showed significant differences for apical RV longitudinal strain (RVAS: -7.5% ± 5.6%, -13.3% ± 4.3%, -14.3% ± 6.3%, P = 0.03). NT pro-BNP was higher in patients with postcapillary PH (4677.0 ± 7764.1 pg/mL, precapillary PH: 1980.3 ± 3432.1 pg/mL, no PH: 367.5 ± 420.4 pg/mL, P = 0.03). Patients with precapillary PH presented significantly more often with ECG RV-stress signs (P = 0.001). Receiver operating characteristics curve analyses displayed the most significant area under the curve (AUC) for RVAS (cut-off < -6.5%, AUC 0.91, P < 0.001), sPAP (cut-off > 33 mmHg, AUC 0.86, P < 0.001) and ECG RV stress signs (AUC 0.83, P < 0.001). The combination of these parameters had a sensitivity of 82.8% and a specificity of 17.2% to detect precapillary PH.
The combination of non-invasive measurements allows feasible assessment of PH and seems beneficial for the differentiation between the pre- and postcapillary form of this disease.
Core tip: We investigated the value of speckle-tracking (ST) analysis of the right ventricle (RV) in patients with suspected pulmonary hypertension. It focuses on a non-invasive model including parameters derived from standard transthorathic echocardiography (TTE) and ST, as well as electrocardiogram (ECG), six minutes walking distance and NT-pro BNP in order to distinguish the precapillary and postcapillary forms of PH. ST-derived apical RV longitudinal strain (RVAS < -6.5%), TTE-derived systolic pulmonary artery pressure (sPAP > 33 mmHg) and ECG RV stress signs were associated with precapillary PH, their combination had a sensitivity of 82.8% and a specificity of 17.2% for the detection of precapillary PH.