Impaired RV Global Longitudinal Strain Is Associated With Poor Long-Term Clinical Outcomes in Patients With Acute Inferior STEMI | Journal Scan

Study Questions:

Is right ventricular (RV) global longitudinal strain (GLS) a better predictor of adverse outcomes in inferior ST-segment elevation myocardial infarction (STEMI) than other measures of RV function?

Methods:

The authors retrospectively identified 282 patients with acute STEMI treated with percutaneous coronary intervention of an acute right coronary artery occlusion, and who also had echocardiography within the first 3 days. In addition to conventional echocardiographic measurements, RV fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), and RV GLS were measured with velocity vector imaging using speckle tracking. Patients were clinically followed for a mean of 54 ± 35 months for a composite of major adverse cardiovascular events (MACE) consisting of hospitalization for heart failure, recurrent MI, target lesion revascularization, or death.

Results:

Of the 282 patients studied, the vast majority were male (n = 212). Clinical evidence of RV infarction on echocardiography or electrocardiogram was seen in 56 (20%) patients. RV GLS was significantly correlated to both RV FAC and TAPSE (r = -0.51 and r = -0.69, respectively, p < 0.001 for both). Abnormal RV systolic function (FAC <35%) was seen in 72 patients (26%). During follow-up, 59 patients experienced MACE. Univariable predictors of MACE were older age, Killip class ≥3, lower left ventricular ejection fraction (LVEF), clinical evidence of RV infarction, RV FAC, TAPSE, and RV GLS. RV GLS ≥-15.5% was associated with a sensitivity of 73%, specificity of 65%, and c-statistic of 0.742 (p < 0.001). After multivariable adjustment for age, Killip class, troponin I, LVEF, and clinical evidence of RV infarction, RV GLS had a higher c-statistic (0.770) than RV FAC (0.749) or TAPSE (0.751). Importantly, RV GLS was an independent predictor of MACE in multivariate models, whereas RV FAC and TAPSE were not. Patients with RV GLS ≥-15.5% had lower survival (74% vs. 89%, p < 0.0001) and MACE-free survival (64% vs. 87%, p < 0.0001).

Conclusions:

RV GLS demonstrated incremental prognostic value over age, LV function, Killip class, troponin I, and clinical evidence of RV infarction.

Perspective:

It has previously been well established that involvement of the RV in inferior MI is associated with worse prognosis. In this study, traditional quantitative markers of RV function did not add to prognostic assessment beyond such important prognostic factors as LVEF and clinical evidence of RV involvement. However, RV GLS did significantly improve prognosis, and those with impaired RV GLS were at markedly increased risk of both MACE and death. Given the increased recognition of the importance of RV function on outcomes in patients with inferior MI, the greater prognostic value of RV GLS than traditional measures in this cohort suggests that this measure may be worthy of increased clinical and research focus.

Keywords: Echocardiography, Electrocardiography, Heart Failure, Hospitalization, Inferior Wall Myocardial Infarction, Percutaneous Coronary Intervention, Stroke Volume, Systole, Troponin I, Ventricular Function, Right, Coronary Occlusion


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