Reverse Left Ventricular Remodelling in ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention: Incidence, Predictors, and Impact on Outcome

Role of Chitinase-3-like Protein 1 in Cardioprotection and Angiogenesis by Post-Infarction Exercise Training

Chitinase-3-like protein 1 (CHI3L1) is a myokine involving tissue remodeling and inflammatory processes. CHI3L1 and its receptor protease-activated receptor 2 (PAR2) are induced by exercise in skeletal muscles. However, it remains unknown if CHI3L1/PAR2 signaling also mediates exercise-induced cardioprotection after myocardial infarction. Twenty-four adult male rats were divided into three groups (n = 8/group), receiving: (1) a sham operation; (2) permanent ligation of left anterior descending coronary artery; and (3) post-MI exercise training with one-week adaptive treadmill exercise for seven days followed by four weeks of aerobic exercise. Left ventricular systolic and end-diastolic pressure indices were measured and cardiac fibrosis, and angiogenesis were examined. Furthermore, HUVEC cells were treated in vitro with AMPK agonist—AICAR (a putative pharmacological memetic of exercise), recombinant human CHI3L1, PAR2 receptor blocker (AZ3451), and PI3K inhibitor (LY294002), respectively. We found that post-MI exercise significantly upregulated CHI3L1, PAR2, pPI3K/PI3K, pAKT/AKT, pERK/ERK, improved cardiac function, and diminished fibrosis. AICAR increased HUVEC tubules formation and upregulated CHI3L1 and PAR2 and these changes were attenuated by PAR2 blocker. In conclusion, post-MI exercise training can effectively activate CHI3L1/PAR2 signaling, which led to the improved myocardial function and enhanced cardiac angiogenesis in the infarcted heart.

Impact of Total Ischemic Time on the Recovery of Regional Wall Motion Abnormality after STEMI in the Modern Reperfusion Era

Background

Total ischemic time (TIT) is an important factor for predicting mortality among patients with ST-segment elevation myocardial infarction (STEMI). However, the correlation between TIT and the extent of wall motion abnormality has not been well studied. Therefore, we investigated changes in the wall motion score index (WMSI) value based on TIT in STEMI patients who underwent primary percutaneous coronary intervention (PCI) and subsequent transthoracic echocardiography.

Methods

STEMI patients who underwent primary PCI and follow-up coronary angiography were analyzed after the exclusion of cases of in-stent restenosis (ISR). WMSI values were calculated by dividing the sum of scores by the number of segments visualized.

Results

A total of 189 patients underwent primary PCI for STEMI, and 151 had no ISR with a median follow-up of 12.3 months. TIT was 180 (117–369) minutes in a subset of 151 patients (mean age of 62 years; 76% male). Among patients without ISR, 109 (72%) demonstrated a decrease in the WMSI value during the follow-up period. The WMSI values of patients with TITs of 180 minutes or less were significantly decreased relative to those among patients with TITs of greater than 180 minutes (p=0.020). Among patients with TITs of 180 minutes or less, the TIT was significantly shorter among those with a reduction in the WMSI value than among those with an increase in the WMSI value (106 [81–124] vs. 133 [100–151] minutes; p=0.018). TIT was an independent predictor for a reduction in the WMSI value among these patients (adjusted hazard ratio: 0.976 (0.957–0.995); p=0.016).

Conclusions

In the modern reperfusion era of STEMI, patients with TITs of 180 minutes or less experienced a significant degree of recovery from regional wall motion abnormalities.

Impact of Reverse Left Ventricular Remodeling on Outcomes of Patients with Anomalous Left Coronary Artery from the Pulmonary Artery after Surgical Correction

The impact of reverse left ventricular remodeling (r-LVR) on clinical outcomes after surgical correction of anomalous left coronary artery from the pulmonary artery (ALCAPA) remains unclear. This study aims to examine the prognostic significance of r-LVR in patients with ALCAPA after surgery. We prospectively identified 61 patients undergoing surgical correction for ALCAPA; 54 patients had adequate echocardiographic image quality with quantitative biplane analysis performed both at baseline and at 30-day postoperative follow-up. Postoperative r-LVR was defined as a reduction of ≥ 10% in left ventricular end-diastolic volume index during follow-up. Cox proportional-hazards regression was used to investigate the independent association of r-LVR and all-cause mortality. Among 54 patients (age: 21.2 ± 7 months; 37% females), r-LVR occurred in 35 patients (64.8%) after surgery. Compared to patients with r-LVR, patients without r-LVR had significantly higher level of N-terminal pro B-type natriuretic peptide (NT-proBNP) [2176 (711, 4219) vs 998 (623, 2145) P < 0.001] and lower survival rate (47.3% vs 82.9%, HR = 5.72 [1.96 to 17.20], P < 0.001) at 1-year follow-up. NT-proBNP (OR = 2.27 [1.67 to 18.3], P = 0.02) was an independent predictor of r-LVR in multivariate analysis. Moreover, r-LVR was significantly associated with a lower rate of all-cause mortality (HR = 0.27 [0.08 to 0.98], P = 0.03) in multivariate analysis, even after adjustment for clinical and echocardiographic variables. R-LVR occurred in more than half of patients with ALCAPA undergoing surgical correction and it was associated with better clinical outcomes. NT-proBNP is an independent predictor of r-LVR.