Teamwork using strain imaging in the echocardiographic assessment of right ventricular systolic function: A cardiac magnetic resonance imaging correlation study

Echocardiography Versus Magnetic Resonance Imaging Quantification and Novel Algorithm for Isolated Severe Tricuspid Regurgitation

Transthoracic echocardiography (TTE) is the first-line tool to evaluate isolated tricuspid regurgitation (TR) but it has limitations and its TR quantification compared with magnetic resonance imaging (MRI) has been studied infrequently. We compared isolated severe TR quantification by TTE against MRI and developed a novel TTE-based algorithm. Isolated TR patients graded severe by TTE and who underwent MRI January 2007 to June 2019 were studied. The TTE and MRI measurements were analyzed by correlation, area under receiver-operative characteristics curve (AUC), and classification and regression tree algorithm of TTE parameters to best identify MRI-derived severe TR (regurgitant volume ≥45 ml and/or fraction ≥50%). A total of 108 of 262 (41%) that were graded as severe TR by TTE also had severe TR by MRI. There were moderate correlations between TTE and MRI in the quantification of TR severity and right atrial size (Pearson r = 0.428 to 0.645) but none to modest correlations between them in right ventricle quantification. The key TTE parameters to identify MRI-derived severe TR in the decision tree regression algorithm were right atrial volume indexed ≥47 ml/m2 and effective regurgitant orifice area ≥0.45 cm2 and especially if there is right ventricle free wall strain ≥ -9.5%. This novel algorithm has an AUC of 0.76% and 79% agreement to detect severe TR by MRI, which higher than the American Society of Echocardiography criteria with AUC 0.68% and 66% agreement (p = 0.006 and p <0.001, respectively). In conclusion, TTE-derived TR and right atrial quantification had moderate correlation and discrimination of severe TR by MRI, from which a novel TTE algorithm was derived, which had incrementally a higher accuracy than contemporary guidelines' criteria alone.

Incremental Value of Global Longitudinal Strain to Michigan Risk Score and Pulmonary Artery Pulsatility Index in Predicting Right Ventricular Failure Following Left Ventricular Assist Devices

BACKGROUND

The incremental utility of right ventricular (RV) strain on predicting right ventricular failure (RVF) following left ventricular assist device (LVAD) implantation, beyond clinical and haemodynamic indices, is not clear.

METHODS

Two hundred and forty-six (246) patients undergoing LVAD implantation, who had transthoracic echocardiograms pre and post LVAD, pulmonary artery pulsatility index (PAPI) measurements and Michigan risk score, were included. We analysed RV global longitudinal strain (GLS) using speckle tracking echocardiography. RVF following LVAD implantation was defined as the need for medical support for >14 days, or unplanned RV assist device insertion after LVAD implantation.

RESULTS

Mean preoperative RV-GLS was -7.8±2.8%. Among all, 27% developed postoperative RVF. A classification and regression tree analysis identified preoperative Michigan risk score, PAPI and RV-GLS as important parameters in predicting postoperative RVF. Eighty per cent (80%) of patients with PAPI <2.1 developed postoperative RVF, while only 4% of patients with PAPI >6.8 developed RVF. For patients with a PAPI of 2.1-3.2, having baseline Michigan risk score >2 points conferred an 81% probability of subsequent RVF. For patients with a PAPI of 3.3-6.8, having baseline RV-GLS of -4.9% or better conferred an 86% probability of no subsequent RVF. The sensitivity and specificity of this algorithm for predicting postoperative RVF were 67% and 93%, respectively, with an area under the curve of 0.87.

CONCLUSION

RV-GLS has an incremental role in predicting the development of RVF post-LVAD implantation, even after controlling for clinical and haemodynamic parameters.