Determinants of right ventricular remodeling following ST-segment elevation myocardial infarction

The optimal definition and prediction nomogram for left ventricular remodelling after acute myocardial infarction

AIMS

Left ventricular (LV) remodelling after acute myocardial infarction (AMI) is associated with heart failure and increased mortality. There was no consensus on the definition of LV remodelling, and the prognostic value of LV remodelling with different definitions has not been compared. We aimed to find the optimal definition and develop a prediction nomogram as well as online calculator that can identify patients at risk of LV remodelling.

METHODS AND RESULTS

This prospective, observational study included 829 AMI patients undergoing percutaneous coronary intervention from January 2015 to January 2020. Echocardiography was performed within the 48 h of admission and at 6 months after infarction to evaluate LV remodelling, defined as a 20% increase in LV end-diastolic volume (LVEDV), a 15% increase in LV end-systolic volume (LVESV), or LV ejection fraction (LVEF) < 50% at 6 months. The impact of LV remodelling on long-term outcomes was analysed. Lasso regression was performed to screen potential predictors, and multivariable logistic regression analysis was conducted to establish the prediction nomogram. The area under the curve, calibration curve and decision curve analyses were used to determine the discrimination, calibration and clinical usefulness of the remodelling nomogram. The incidences of LV remodelling defined by LVEDV, LVESV and LVEF were 24.85% (n = 206), 28.71% (n = 238) and 14.60% (n = 121), respectively. Multivariable Cox regression models demonstrated that different definitions of LV remodelling were independently associated with the composite endpoint. However, only remodelling defined by LVEF was significantly connected with long-term mortality (hazard ratio = 2.78, 95% confidence interval 1.41-5.48, P = 0.003). Seven variables were selected to construct the remodelling nomogram, including diastolic blood pressure, heart rate, AMI type, stent length, N-terminal pro brain natriuretic peptide, troponin I, and glucose. The prediction model had an area under the receiver operating characteristics curve of 0.766. The calibration curve and decision curve analysis indicated consistency and better net benefit in the prediction model.

CONCLUSIONS

LV remodelling defined by LVEDV, LVESV and LVEF were independent predictors for long-term mortality or heart failure hospitalization in AMI patients after percutaneous coronary intervention. However, only remodelling defined by LVEF was suitable for predicting all-cause death. In addition, the nomogram can provide an accurate and effective tool for the prediction of postinfarct remodelling.

Prognostic Relevance of Right Ventricular Remodeling after ST-Segment Elevation Myocardial Infarction in Patients Treated With Primary Percutaneous Coronary Intervention

ST-segment elevation myocardial infarction (STEMI) often leads to changes in right ventricular (RV) function and size over time. The prognostic implications of RV remodeling after STEMI, however, are unknown. RV remodeling in patients who underwent STEMI with primary percutaneous coronary intervention (PCI) was defined by RV end-systolic area (RV ESA) change at 6 months after STEMI compared with baseline. The optimal threshold of RV ESA change (≥40%) to define RV remodeling was derived from spline curve analysis. Long-term outcomes were compared between patients with and without RV remodeling. A total of 2,280 patients were analyzed (mean age 60 ± 11 years, 76% were men). RV remodeling was present in 315 patients (14%). After a median follow-up of 76 months (interquartile range 51 to 106 months), 271 patients (12%) died (primary end point) and the composite end point of all-cause mortality and HF hospitalization (secondary end point) was observed in 292 patients (13%). After adjustment for various risk factors, including tricuspid annular plane systolic excursion (TAPSE), post-STEMI RV remodeling was independently associated with a higher risk of all-cause mortality (hazard ratio [HR] = 1.44, 95% confidence interval [CI] 1.02 to 2.02, p = 0.038) and the composite of all-cause mortality and HF hospitalization (HR = 1.41, 95% CI 1.02 to 1.96, p = 0.040). Finally, patients with RV remodeling had a significantly lower survival rate (Log-rank, p = 0.006) and event-free survival rate than those without RV remodeling during follow-up (log-rank, p = 0.006). RV post-infarct remodeling is associated with mortality and HF hospitalization, independent of RV systolic function.

Role of N-terminal pro-B-type natriuretic peptide and troponin T in predicting right ventricular recovery in myocardial infarction

OBJECTIVES

The determinants of right ventricular (RV) recovery after successful revascularization in ST-elevation myocardial infarction (STEMI) patients are not clear. Besides, the relationship between Troponin T (TnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP) and improvement in RV function is also unknown. This study hypothesizes that a lower TnT and NT-proBNP level would be associated with RV recovery.

METHODS

One hundred forty-eight STEMI patients were included in our study. Echocardiography were performed before and 12-18 weeks after discharge. Patients were divided into three groups according to the changes in tricuspid annular plane systolic excursion (TAPSE) as 53 patients with ≥10% change, 41 patients with 1-9% change, and 54 patients ≤0% change. RV recovery was accepted as ≥10% TAPSE improvement and the predictors of RV recovery were investigated.

RESULTS

RV recovery was detected in 35.8% of the patients. Low baseline left ventricular ejection fraction (OR: 0.91 [0.84-0.98], p=0.023), NT-proBNP (OR: 0.93 [0.89-0.98], p=0.014), TnT (OR: 0.84 [0.68-0.93], p=0.038), inferior myocardial infarction (OR: 2.66 [1.10-6.40], p=0.028), wall motion score index ratio (OR: 0.93 [0.88-0.97], p=0.002) and post-percutaneous coronary intervention TIMI flow 3 (OR: 5.84 [1.41-24.22], p=0.015) were determined as independent predictors of RV recovery. Being in the high TnT group 4.2 times, and being in the high NT-proBNP group 5.3 times could predict the failure to achieve RV recovery. Furthermore, when high TnT level was combined with high NT-proBNP level, the odds ratio of failure to achieve RV recovery was the highest (OR: 8.03 [2.59-24.89], p<0.001).

CONCLUSIONS

Lower TnT and lower NT-proBNP level was associated with better improvement in RV function in STEMI patients.

Right coronary artery ligation in mice: a novel method to investigate right ventricular dysfunction and biventricular interaction

Right ventricular (RV) dysfunction can lead to complications after acute inferior myocardial infarction (MI). However, it is unclear how RV failure after MI contributes to left-sided dysfunction. The aim of the present study was to investigate the consequences of right coronary artery (RCA) ligation in mice. RCA ligation was performed in C57BL/6JRj mice ( n = 38). The cardiac phenotypes were characterized using high-resolution echocardiography performed up to 4 wk post-RCA ligation. Infarct size was measured using 2,3,5-triphenyltetrazolium chloride staining 24 h post-RCA ligation, and the extent of the fibrotic area was determined 4 wk after MI. RV dysfunction was confirmed 24 h post-RCA ligation by a decrease in the tricuspid annular plane systolic excursion ( P < 0.001) and RV longitudinal strain analysis ( P < 0.001). Infarct size measured ex vivo represented 45.1 ± 9.1% of the RV free wall. RCA permanent ligation increased the RV-to-left ventricular (LV) area ratio ( P < 0.01). Septum hypertrophy ( P < 0.01) was associated with diastolic septal flattening. During the 4-wk post-RCA ligation, LV ejection fraction was preserved, yet it was associated with impaired LV diastolic parameters ( E/ E', global strain rate during early diastole). Histological staining after 4 wk confirmed the remodeling process with a thin and fibrotic RV. This study validates that RCA ligation in mice is feasible and induces RV heart failure associated with the development of LV diastolic dysfunction. Our model offers a new opportunity to study mechanisms and treatments of RV/LV dysfunction after MI. NEW & NOTEWORTHY Right ventricular (RV) dysfunction frequently causes complications after acute inferior myocardial infarction. How RV failure contributes to left-sided dysfunction is elusive because of the lack of models to study molecular mechanisms. Here, we created a new model of myocardial infarction by permanently tying the right coronary artery in mice. This model offers a new opportunity to unravel mechanisms underlying RV/left ventricular dysfunction and evaluate drug therapy.

Right ventricular function in patients presenting with non-ST-segment elevation myocardial infarction undergoing an invasive approach

Background

Right ventricular involvement in ST segment elevation myocardial infarction (STEMI) entails an increased morbidity and mortality. However, very scarce data is present on its affection in the setting of non-ST segment elevation myocardial infarction (NSTEMI).

Aim

To assess the affection of right ventricular function in patients presenting with NSTEMI undergoing an invasive procedure.

Subjects and methods

One hundred and fifty patients admitted with a first NSTEMI and eligible for reperfusion therapy via invasive percutaneous coronary intervention. These patients were divided in two groups; group A including patients with normal RV function, and group B including patients with impaired RV function as diagnosed by tricuspid annular plane systolic excursion (TAPSE) cutoff value < 17 mm. All patients underwent angioplasty and were followed up in-hospital and for 3 months.

Results

RV dysfunction occurred in ninety-five (61.3%) patients of the study population. Significant improvement occurred to TAPSE after 3 months in comparison to TAPSE at baseline (15.45 ± 3.21 versus 17.09 ± 4.17 mm). Those with impaired RV function showed improvement of TAPSE after three months as compared to baseline (13.62 ± 2.58 vs 17.16 ± 3.64 p = 0.008). Multivariate analysis determined the independent predictors of RV dysfunction as RVEDD > 26 mm, RVFAC < 35%, RAA > 20 cm², and TAPSE < 17 mm.

Conclusion

RV dysfunction is not uncommon in NSTEMI when using the definition of TAPSE < 17 mm. Following up RV function by TAPSE, showed significant improvement after 3 months with successful PCI as compared to baseline. We recommend assessing and following up RV function in all patients admitted with a NSTEMI.

The effects of urgent percutaneous coronary intervention on right ventricular systolic functions in non-ST-elevation acute coronary syndromes

BACKGROUND

Although the importance of the right ventricle (RV) involvement has been known for many years in patients with ST-elevation myocardial infarction (STEMI), it is scarce in non-ST-elevation acute coronary syndrome (NSTE-ACS).

OBJECTIVES

We aimed to investigate the effects of urgent percutaneous coronary intervention (PCI) on the RV systolic functions in patients with NSTE-ACS.

MATERIALS AND METHODS

Ninety-five patients diagnosed with NSTE-ACS and who underwent urgent PCI were prospectively investigated. RV systolic functions were analyzed and compared before and after PCI in all patients by using RV index of myocardial performance (RIMP), tricuspid annular plane systolic excursion (TAPSE), two-dimensional (2D) RV fractional area change (FAC), and isovolumic acceleration (IVA) parameters with transthoracic echocardiography.

RESULTS

Among 95 NSTE-ACS patients, 31 had impaired RIMP, 13 had impaired TAPSE, 8 had decreased 2D FAC, and 32 had impaired IVA values at baseline. There was a significant increase in 2D FAC and IVA values after PCI.

CONCLUSIONS

The right ventricular functions may also be affected in patients with NSTE-ACS, and urgent PCI has a significant effect on the recovery of right ventricular systolic functions in patients with NSTE-ACS.