QRS Score at Presentation Electrocardiogram Is Correlated With Infarct Size and Mortality in ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention

Relationship between the Selvester QRS Score and Coronary Microvascular Dysfunction Assessed by the Index of Microcirculatory Resistance

Objective The index of microvascular resistance (IMR) is an invasive method for quantifying the coronary microvasculature independent of the presence and degree of epicardial stenosis during cardiac catheterization, whereas the Selvester QRS score, which is related to myocardial damage, is a relatively simple and non-invasive measurement procedure. We investigated the relationship between the QRS score and coronary microvascular dysfunction (CMD) assessed via IMR. Methods Data from 74 patients who underwent invasive coronary physiological measurements were retrospectively reviewed. Using a coronary wire, we measured IMR by the hyperemic mean transit time and distal coronary pressure. We also determined a simplified QRS score following the Selvester QRS score criteria by 12-lead electrocardiography. After determining the best cutoff value for the QRS score to predict IMR ≥25, which was defined as CMD by the Coronary Vasomotion Disorders International Study Group, patients were categorized into the QRS score ≥3 (n=16) and the QRS score 0-2 (n=58) groups. Results IMR in the QRS score ≥3 group was significantly higher in comparison to the QRS score 0-2 group (31; IQR: 19-57 vs. 20; IQR: 14-29, p<0.01). The percentage of patients with IMR ≥25 in the QRS score ≥3 group was significantly higher than that in the QRS score 0-2 group (69% vs. 34%, p=0.01). Conclusion A higher QRS score was associated with CMD, as estimated by IMR. The Selvester QRS score is noninvasive parameter that is potentially useful for predicting CMD.

Culprit Lesion Morphology of Rapidly Progressive and Extensive Anterior-Wall ST-Segment Elevation Myocardial Infarction

BACKGROUND

Rapidly progressive, extensive myocardial injury/infarction (RPEMI) beyond the concept of wave-front phenomenon can be observed even when achieving timely reperfusion; however, the pathogenesis of RPEMI remains unknown. This retrospective study investigated clinical and lesion characteristics of RPEMI, focusing on culprit-lesion morphology (CLM).

METHODS

Among patients with extensive anterior-wall ST-segment elevation myocardial infarction due to proximal left anterior descending artery lesions who had reperfusion within 3 hours of symptom onset, 60 patients undergoing both intravascular ultrasound and cardiac magnetic resonance imaging were enrolled. Myocardial injury/infarction before reperfusion therapy was assessed by QRS scores at hospitalization electrocardiogram, and the extent of myocardial injury/infarction was evaluated by cardiac magnetic resonance imaging, which measured area at risk, infarct size, myocardial salvage index, microvascular obstruction, and left ventricular ejection fraction. RPEMI was defined as lower left ventricular ejection fraction (less median value) with microvascular obstruction.

RESULTS

Despite comparable onset-to-door and onset-to-reperfusion times and area at risk, patients with RPEMI showed higher QRS scores at hospitalization (5 [4.3-6] versus 3 [2-4], P<0.001) and infarct size (26.5±9.1 versus 20.4±10.5%, P=0.04), and a tendency toward lower myocardial salvage index (0.27±0.14 versus 0.36±0.20, P=0.10) compared with those without. Patients with versus without RPEMI more frequently observed specific CLM on intravascular ultrasound, characterized by the combination of vulnerable plaques, plaque ruptures, and/or large thrombi. When stratified by CLM-score composed of these 3 criteria, higher CLM-scores were or tended to be associated with higher QRS scores and incidence of RPEMI. In multivariate analyses including no-reflow phenomenon and final coronary-flow deterioration, increased CLM-score (≥2) was independently associated with high QRS scores and RPEMI (odd ratio 11.25 [95% CI, 2.43-52.00]; P=0.002).

CONCLUSIONS

Vulnerable CLM was a consistent determinant of advanced myocardial injury/infarction both before and after reperfusion therapy and may play a pivotal role in the development of RPEMI.

Prognostic Significance of a Combination of QRS Score and E/e' Obtained 2 Weeks After the Onset of ST-Elevation Myocardial Infarction

BACKGROUND

The early mitral inflow velocity to mitral early diastolic velocity ratio (E/e') and electrocardiogram (ECG) determination of QRS score are useful for risk stratification in patients with ST-elevation myocardial infarction (STEMI).Methods and Results:In this study, 420 consecutive patients (357 male; mean [±SD] age 63.6±12.2 years) with first-time STEMI who successfully underwent primary percutaneous coronary intervention within 12 h of symptom onset were followed-up for 5 years (median follow-up 67 months). Echocardiography, ECG, and blood samples were obtained 2 weeks after onset. Infarct size was estimated by the QRS score after 2 weeks (QRS-2wks) and creatine phosphokinase-MB concentrations (peak and area under the curve). The primary endpoint was death from cardiac causes or rehospitalization for heart failure (HF). During follow-up, 21 patients died of cardiac causes and 62 had HF. Multivariate Cox proportional hazard analysis showed that mean E/e' (hazard ratio [HR] 1.152; 95% confidence interval [CI] 1.088-1.215; P<0.0001), QRS-2wks (HR 1.153; 95% CI 1.057-1.254; P<0.0001), and hypertension (HR 1.702; 95% CI 1.040-2.888; P=0.03) were independent predictors of the primary endpoint. Kaplan-Meier curve analysis showed that patients with QRS-2wks >4 and mean E/e' >14 were at an extremely high risk of cardiac death or HF (log rank, χ²=116.3, P<0.0001).

CONCLUSIONS

In patients with STEMI, a combination of QRS-2wks and mean E/e' was a simple but useful predictor of cardiac death and HF.

Both baseline Selvester QRS score and change in QRS score predict prognosis in patients with acute ST-segment elevation myocardial infarction after percutaneous coronary intervention

We aimed to demonstrate the prognostic value of Selvester QRS scores in patients with acute ST-segment elevation myocardial infarction (STEMI).

Differences in the Selvester QRS score after primary PCI strategy and conservative treatment for STEMI patients with negative T waves

BACKGROUND

According to current guidelines, the main indications for PCI in patients with STEMI are ST-segment deviations and defined time from the onset of symptoms. Negative T wave at admission can be a sign of prolonged ischemia or spontaneous reperfusion. In both situations, the urgent intervention is questionable. We evaluated the infarct size and in-hospital mortality in STEMI patients with negative T wave in cases of primary PCI strategy compared with conservative treatment.

METHODS

A retrospective analysis of 116 STEMI patients with negative T wave at the presenting ECG was performed. Sixty-eight patients (59%) underwent primary PCI strategy (PCI group), and 48 (41%) were treated conservatively (non-PCI group). The infarct size estimated by using the Selvester score, and in-hospital mortality were evaluated.

RESULTS

The difference between Selvester score values at admission and at discharge in the non-PCI group was statistically significant (1.48; 95% CI 0.694-2.27), while no significant difference was observed in the PCI group (-0.07; 95% CI -0.546-0.686). The in-hospital mortality was higher in the non-PCI group; however, the numbers were relatively small: PCI 2 (2.9%) and non-PCI 5 (10.4%).

CONCLUSION

In this study, we showed a reduction in the infarct size estimated by Selvester score in STEMI patients with negative T wave who were treated conservatively, while there was no significant change in the infarct size after primary PCI strategy. The higher mortality in patients treated conservatively could be attributed to higher age and comorbidities in the non-PCI group. It seems that conservative treatment strategy might be an option in STEMI patients with negative T wave.

PPARα activation alleviates damage to the cytoskeleton during acute myocardial ischemia/reperfusion in rats

The cytoskeleton serves an important role in maintaining cellular morphology and function, and it is a substrate of calpain during myocardial ischemia/reperfusion (I/R) injury (MIRI). Calpain may be activated by endoplasmic reticulum (ER) stress during MIRI. The activation of peroxisome proliferator-activated receptor α (PPARα) may inhibit ischemia/reperfusion damage by regulating stress reactions. The present study aimed to determine whether the activation of PPARα protects against MIRI-induced cytoskeletal degradation, and investigated the underlying mechanism involved. Wistar rats were pretreated with or without fenofibrate and subjected to left anterior descending coronary artery ligation for 45 min, followed by 120 min of reperfusion. Calpain activity and the expression of PPARα, desmin and ER stress parameters were evaluated. Electrocardiography was performed and cardiac function was evaluated. The ultrastructure was observed under transmission electron microscopy. I/R significantly induced damage to the cytoskeleton in cardiomyocytes and cardiac dysfunction, all of which were improved by PPARα activation. In addition, I/R increased ER stress and calpain activity, which were significantly decreased in fenofibrate-pretreated rat heart tissue. The results suggested that PPARα activation may exert a protective effect against I/R in the myocardium, at least in part via ER stress inhibition. Suppression of ER stress may be an effective therapeutic target for protecting the I/R myocardium.