The predictive value of R-wave peak time on no-reflow in patients with ST-elevation myocardial infarction treated with a primary percutaneous coronary intervention

Utility of electrocardiogram to predict the occurrence of the no-reflow phenomenon in patients undergoing primary percutaneous coronary intervention (PPCI): a systematic review and meta-analysis

Background

The no-reflow phenomenon affects about one out of five patients undergoing Primary Percutaneous Coronary Intervention (PPCI). As the prolonged no-reflow phenomenon is linked with unfavorable outcomes, making early recognition is crucial for effective management and improved clinical outcomes in these patients. Our review study aimed to determine whether electrocardiogram (ECG) findings before PCI could serve as predictors for the occurrence of the no-reflow phenomenon.

Methods and materials

We systematically searched MEDLINE, Scopus, and Embase to identify relevant studies. The random-effect model using inverse variance and Mantel-Haenszel methods were used to pool the standardized mean differences (SMD) and odds ratios (OR), respectively.

Result

Sixteen eligible articles (1,473 cases and 4,264 controls) were included in this study. Based on our meta-analysis of baseline ECG findings, the no-reflow group compared to the control group significantly had a higher frequency of fragmented QRS complexes (fQRS) (OR (95% CI): 1.35 (0.32-2.38), P-value = 0.01), and Q-waves (OR (95% CI): 1.97 (1.01-2.94), P-value <0.001). Also, a longer QRS duration (QRSD) (SMD (95% CI): 0.72 (0.21, 1.23), p-value <0.001) and R wave peak time (RWPT) (SMD (95% CI): 1.36 (0.8, 1.93), P < 0.001) were seen in the no-reflow group. The two groups had no significant difference regarding P wave peak time (PWPT), and P wave maximum duration (Pmax) on baseline ECG.

Conclusion

Our findings suggest that prolonged QRSD, delayed RWPT, higher fQRS prevalence, and the presence of a Q wave on baseline ECG may predict the occurrence of the no-reflow phenomenon in patients undergoing PPCI.

R wave peak time and no reflow following primary percutaneous coronary intervention: Immediate and short-term outcomes

BACKGROUND

No reflow (NR) remains an important constraint in management of ST elevation myocardial Infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). Most ECG parameters validated till date including ST resolution are postprocedural. R wave peak time (RWPT) is a dynamic parameter and reflects conduction delay in ischaemic myocardium in selected leads supplied by infarct related artery (IRA). The present study was undertaken to see whether preprocedural RWPT per se or RWPT following primary PCI can predict persistence of NR along with immediate and short-term clinical outcome.

METHODS

200 patients were enrolled after exclusion. Clinical, Biochemical, ECG parameters including RPWT and angiographic parameters (pre- and post-procedure) were recorded. ECG papers was analysed using digital image processing software (http://imagej.nih.gov/ij/). All patients were followed up for 6 months.

RESULTS

NR was observed in 35% of the patients. Age, Diabetes, symptom to balloon time, higher thrombus burden, peak CPK-MB level (pre and post procedure) were significantly higher in NR group. On ECG analysis, baseline RWPT, QRS duration and pathological Q wave were significantly higher in NR group. On multivariate analysis, age (OR 1.10 CI 1.00-1.21 P = 0.04), thrombus grade ≥ 3 in IRA (OR 12.38 CI 2.08-73.58 P = 0.006), symptom to balloon time (OR 2.18 CI 1.6-3.0 P < 0.001) and baseline RWPT on ECG [OR 1.86 CI 1.24-2.78, P = 0.003] were found to be independent predictors of NR. Increase in RWPT following primary PCI was found to both highly sensitive and specific for diagnosing persistence of NR after primary PCI. Follow up at the end of 6 months has shown that patients with increased RWPT following primary PCI had worse short-term cardiovascular outcomes compared to those with decreased RWPT following primary PCI.

CONCLUSION

Baseline RWPT is a significant predictor of NR in patients of STEMI undergoing primary PCI. A persistently increased RWPT following primary PCI is also a highly sensitive and specific ECG marker of persistence of NR which is associated with adverse short-term clinical outcome.

No-reflow phenomenon in ST-segment elevation myocardial infarction: still the Achilles' heel of the interventionalist

Improvements in systems, technology and pharmacotherapy have significantly changed the prognosis over recent decades in patients presenting with ST-segment elevation myocardial infarction. These clinical achievements have, however, begun to plateau and it is becoming increasingly necessary to consider novel strategies to further improve outcomes. Approximately a third of patients treated by primary percutaneous coronary intervention for ST-segment elevation myocardial infarction will suffer from coronary no-reflow (NR), a condition characterized by poor myocardial perfusion despite patent epicardial arteries. The presence of NR impacts significantly on clinical outcomes including left ventricular dysfunction, heart failure and death, yet conventional management algorithms neither assess the risk of NR nor treat NR. This review will provide a contemporary overview on the pathogenesis, diagnosis and treatment of NR.

Identifying the most important ECG predictors of reduced ejection fraction in patients with suspected acute coronary syndrome

BACKGROUND

Non-invasive screening tools of cardiac function can play a significant role in the initial triage of patients with suspected acute coronary syndrome. Numerous ECG features have been previously linked with cardiac contractility in the general population. We sought to identify ECG features that are most predictive for real-time screening of reduced left ventricular ejection fraction (LVEF) in the acute care setting.

METHODS

We performed a secondary analysis of a prospective, observational cohort study of patients evaluated for suspected acute coronary syndrome. We included consecutive patients in whom an echocardiogram was performed during indexed encounter. We evaluated 554 automated 12-lead ECG features in multivariate linear regression for predicting LVEF. We then used regression trees to identify the most important predictive ECG features.

RESULTS

Our final sample included 297 patients (aged 63 ± 15, 45% females). The mean LVEF was 57% ± 13 (IQR 50%-65%). In multivariate analysis, depolarization dispersion in the horizontal plane; global repolarization dispersion; and abnormal temporal indices in inferolateral leads were all independent predictors of LVEF (R² = 0.452, F = 6.679, p < 0.001). Horizontal QRS axis deviation and prolonged ventricular activation time in left ventricular apex were the most important determinants of reduced LVEF, while global QRS duration was of less importance.

CONCLUSIONS

Poor R wave progression in precordial leads with dominant QS pattern in V3 is the most predictive feature of reduced LVEF in suspected ACS. This feature constitutes a simple visual marker to aid clinicians in identifying those with impaired cardiac function.