Fragmented QRS and mortality in patients undergoing percutaneous intervention for ST-elevation myocardial infarction: Systematic review and meta-analysis

The Relationship between Fragmented QRS and Myocardial Injury in Patients with Acute Carbon Monoxide Poisoning

Background and Objectives: Carbon monoxide (CO) intoxication is one of the most common causes of poisoning-related deaths and complications. Myocardial injury is an important complication of CO poisoning. In our study, we aimed to evaluate the relationship between the presence and prevalence of fragmented QRS (fQRS) and myocardial injury in patients with CO intoxication. Materials and Methods: We retrospectively evaluated patients who presented to the emergency department of our tertiary care center with CO intoxication between January 2020 and December 2023. In our study, we performed subgroup analyses according to the presence of myocardial injury and fQRS. We evaluated the parameters and risk factors associated with myocardial injury. Results: Myocardial injury was detected in 44 patients, and fQRS was detected in 38 patients. In the myocardial injury (+) group, the fQRS rate was 38.6%, and the median number of leads with fQRS was 3 (2-6) and was significantly higher than in the myocardial injury (-) group (p < 0.001). We found that carboxyhemoglobin had a significant positive correlation with troponin (p = 0.001) and pro-B-type natriuretic peptide (proBNP) (p = 0.009). As a result of multivariate analysis, we determined that age, creatinine, proBNP, fQRS, and ≥3 leads with fQRS are independent risk factors for myocardial injury. Conclusions: Myocardial injury in CO intoxication patients is associated with proBNP, the presence of fQRS, and the number of leads with fQRS. Age, creatinine level, proBNP, the presence of fQRS, and ≥3 leads with fQRS are independent risk factors for myocardial injury in patients with CO intoxication.

Significance of fragmented QRS and predictors of outcome in ST-elevation myocardial infarction

Background

Fragmented QRS (fQRS) might be associated with certain characteristics in ST-elevation myocardial infarction (STEMI) patients and inhospital adverse events.

Materials and Methods

A sum of 500 patients were gone over retrospectively. Patients with STEMI, all undergone percutaneous coronary intervention, were grouped as fQRS (-) and fQRS (+). Characteristics of the patients, major adverse cardiac event (MACE), death in hospital, nonfatal myocardial infarction (MI), stent thrombosis, slow flow myocardial perfusion, development of ventricular tachycardia (VT) and fibrillation, cardiogenic shock and cardiopulmonary arrest were filtered.

Results

FQRS (-) group was composed of 207 patients whose mean age was 61.1 ± 12.1, whereas 293 patients were there in fQRS (+) with a mean age of 66.7 ± 10.6 (P < 0.001). Thrombolysis in MI (TIMI) (P < 0.01), the global registry of acute coronary events (GRACE) (P < 0.01) scores, white blood cell count, neutrophil/lymphocyte ratio, MACE and the ratio of death in hospital and VT in the hospital were significantly higher in fQRS (+) group (P < 0.001, for remaining all). In multivariate logistic regression analysis, TIMI scores above 2 and GRACE scores above 109 were determined as independent predictors of MACE in the entire patient group (odds ratio [OR]: 2.022; 95% confidence interval [CI]; 1.321-3.424, P = 0.003; OR: 1.712; 95% CI: 1.156-2.804, P = 0.008).

Conclusion

FQRS (+) and fQRS (-) patients markedly differ from each other in terms of certain demographic and clinical features and TIMI and GRACE scores have a significant predictive value for MACE in all STEMI patients' group.

QRS fragmentation does not predict mortality in survivors of acute myocardial infarction

BACKGROUND

Despite advances in coronary revascularization and in heart failure management, myocardial infarction survivors remain at substantially increased mortality risk. Precise risk assessment and risk-adapted follow-up care are crucial to improve their outcomes. Recently, the fragmented QRS complex, i.e. the presence of additional spikes within the QRS complexes on a 12-lead electrocardiogram, has been discussed as a potential non-invasive risk predictor in cardiac patients.

HYPOTHESIS

The aim of this study was to evaluate the prognostic meaning of the fragmented QRS complex in myocardial infarction survivors.

METHODS

609 patients with narrow QRS complexes <120 ms were included in a prospective cohort study while hospitalized for myocardial infarction and followed for 5 years.

RESULTS

The prevalence of the fragmented QRS complex in these patients amounted to 46.8% (285 patients). These patients had no increased hazard of all-cause death (HR 0.84, 95%-CI 0.45-1.57, p = 0.582) with a mortality rate of 6.0% compared to 7.1% in patients without QRS fragmentations. Furthermore, the risks of cardiac death (HR 1.28, 95%-CI 0.49-3.31, p = 0.613) and of non-cardiac death (HR 0.6, 95%-CI 0.26-1.43, p = 0.25) were not significantly different in patients with QRS fragmentations. However, patients with QRS fragmentations had increased serum creatine kinase concentrations (1438U/l vs. 1160U/l, p = 0.039) and reduced left ventricular ejection fractions (52% vs. 54%, p = 0.011).

CONCLUSIONS

The hypothesis that QRS fragmentation might be a prognostic parameter in survivors of myocardial infarction was not confirmed. But those with QRS fragmentation had larger myocardial infarctions, as measured by creatine kinase and left ventricular ejection fraction.

Fragmented QRS as a predictor of hypertensive crisis in patients with newly diagnosed essential hypertension: 4-year follow-up data

BACKGROUND

Hypertensive crisis (HC) is a life-threatening condition in patients with hypertension (HT). However, there is no electrocardiography (ECG) marker that can predict which hypertensive patient may develop HC. The fragmented QRS (fQRS) complex is an important prognostic marker in ECG that might be predict cardiovascular events and mortality. Our study aimed to investigate whether fQRS can predict the development of HC in patients with HT, within 4 years of follow-up.

METHODS

Newly diagnosed patients with essential HT were recruited for the study from an outpatient clinic. The patients were divided into two groups according to the presence of HC: HC (+) and HC (-). During follow-up, the relationship between fQRS and HC was evaluated.

RESULTS

The study group included 504 patients with newly diagnosed HT. During the follow-up period, HC occurred in 98 of the patients. In 57 (11.30%) patients, fQRS was observed on ECG; fQRS was detected in the ECG of 19 (19.38%) of the HC (+) patients (p = 0.008). The results of multivariate logistic regression analysis showed that fQRS (p < 0.001) was as independent predictor for HC development. Kaplan-Meier analysis further demonstrated that the presence of fQRS affects the development of hypertensive urgency in hypertensive patients (log-rank p < 0.001).

CONCLUSION

In patients with newly diagnosed HT, the presence of fQRS was found to be an independent predictor of HC.

Electrocardiographic Patterns of Depolarization Abnormalities Help to Identify Reduced Left Ventricular Ejection Fraction

The aim of the study was to investigate the relationship between a decrease in the left ventricular ejection fraction (EF) and traditional ECG signs associated with structural changes of the myocardium (pathological Q wave, ventricular arrhythmias) and relatively new and poorly understood (fragmented QRS complex (fQRS), early repolarization pattern (ERP)) and evaluate their significance for identifying patients with mildly reduced EF (mrEF). The study included 148 patients who were treated and examined at the Almazov Medical Research Center. FQRS, ERP, pathological Q wave, and premature ventricular contractions (PVC) were described in the analysis of the ECG, and the results of echocardiography and statistical data were analyzed: Fisher’s test and chi-square, correlation analysis, and ROC analysis. According to the level of EF, patients were divided into three groups: group 1—patients with low EF (lEF) (less than 40%), group 2—patients with mildly reduced EF (mrEF) (40–49%); group 3—patients with preserved EF (pEF) (more than 50%). In the first group (EF), fQRS was registered in 16 (51.6%) patients, in the mrEF in 16 (18.2%). Pathological Q wave was detected in lEF in 20 (65%), in mrEF in 10 (35%), 15 (18%), in pEF in 15 (18%). The fQRS has been found to be more important in identifying patients with mrEF. In lEF in 2 (6.5%) patients, in mrEF in 2 (6.9%), in pEF in 11 (12.5%). There was no relationship between ERP, the amount of PVC, and the presence of ventricular tachycardia with EF. FQRS is significantly more common occurred with a decrease in EF and may be a marker of a mrEF. Thus, fQRS is associated with mrEF and pay close attention in routine clinical practice to identify patients at high risk of developing systolic dysfunction.

The relation between QRS complex fragmentation and segmental abnormalities of the myocardial contractility in patients with coronary artery disease

Background

Fragmented QRS (fQRS) is defined as any QRS complex with duration of less than 120 ms (ms) and at least one notch in the R or S wave in two or more leads belonging to the same coronary territory. The fQRS represents a delay in ventricular conduction caused by a myocardial scar associated to arrhythmic events.

Methods

This is a descriptive, retrospective, cross-sectional study of a total of 123 patientsadmitted with ischemic heart disease. The aim was to correlate the presence of fQRS in a conventional 12-leads electrocardiogram (ECG) with myocardial regional motility disorders.

Results

A total of 62% of the patients were male, the mean age was 63 ± 12 SD. fQRS was observed in 44% (64% men and 36% women), the most frequent location being the inferior wall (61%), followed by the anteroseptal and lateral walls (14% for both). Of the 36 patients with fQRS, 30 had segmental disorders, while 6 did not. Of the 45 patients without fQRS, 28 had segmental disorders, but 17 did not, which gives us a sensitivity of 52% (moderate SnNout) and specificity of 74% (high SpPin), with a positive predictive value of 83%, a negative predictive value of 38% and a prevalence of 72%.

Conclusion

The presence of fQRS in the ECG has high specificity and a high positive predictive value of the existence of segmental myocardial motility disorders in patients with documented coronary artery disease.

Different associations between left atrial size and 2.5-year clinical outcomes in patients with anterior versus non-anterior wall ST-elevation myocardial infarction

Objective

To investigate associations between left atrial diameter (LAD) and long-term outcomes in patients with anterior or non-anterior wall ST-elevation myocardial infarction (STEMI).

Methods

Patients with STEMI were included in this secondary analysis of data from a prospective cohort study in which the primary outcome was major adverse cardiovascular event (MACE) occurrence during a 2.5-year follow-up. A LAD cut-off value was obtained through receiver operating characteristic curve analysis. Kaplan-Meier curve and Cox regression analyses were applied. Subgroup Cox regression analysis was also performed, with patients stratified based on left ventricular diastolic diameter (LVEDD, > 55 mm and ≤55 mm). The relationship between LAD and outcomes in patients with anterior or non-anterior wall STEMI was explored using restricted cubic spline functions.

Results

Out of 464 patients, adjusted Cox regression showed that dichotomous (>40 mm) LAD was significantly associated with MACE (hazard ratio 2.978, 95% confidence interval 1.763, 5.030) in patients with anterior wall but not non-anterior wall STEMI. The association was not different between normal and enlarged LVEDD groups.

Conclusions

A left atrium > 40 mm may indicate higher risk of MACE in patients with anterior wall STEMI, even in patients with normal left ventricular structure. This relationship was not observed in patients with non-anterior wall STEMI.

Association between fragmented QRS and left ventricular dysfunction in acromegaly patients

Background: In acromegaly patients; it has been observed that heart failure may develop even in the absence of predisposing factors such as hypertension, diabetes mellitus, so a specific acromegalic cardiomyopathy has been suggested. We aimed to evaluate the fQRS frequency in acromegaly patients and the left ventricular (LV) functions of acromegaly patients with fQRS.Methods: Our study included 60 acromegalic patients. Each patient underwent conventional echocardiography and tissue Doppler imaging. The patients included were separated into two groups: those with (n:23) and without (n:37) fQRS.Results: Significant differences were identified between fQRS(+) and fQRS (-) groups with respect to disease duration (p < .001), Left ventricular end diastolic volume (EDV) (p < .001), E velocity (p < .001), E\A ratio (p < .001), E' velocity (p < .001), E/E' ratio (p < .001), isovolumic relaxation time (IVRT) (p < .001), MPI (p < .001). Disease duration (odds ratio [OR]: 2.120 (1.023-1.703 95% confidence interval [CI]), p = .002), E' (OR:3.029 (1.013-1.703 95% CI) p = .004) and fQRS (OR:4.59 (1.94-10.87 95% CI), p = .001) were identified as the independent predictors of myocardial performance index (MPI). However, disease duration (OR:1.078 (1.030-1.128 95% CI), p = .001), E/E' (OR: 1.43 (1.22-1.97 95% CI), p = .001), IVRT (OR:1.65 (1.32-2.06 95% CI), p = .001) and MPI (OR:1.014 (1.004-1.024 95% CI), p = .002) were the independent predictors of fQRS.Conclusions: fQRS was frequent and an independent predictor of MPI that was independelty associated with LV dysfunction in patients with acromegaly. In light of these findings the presence of fQRS is thought to be an indicator of acromegalic CMP development.

Fragmented QRS predicts reperfusion failure and in-hospital mortality in ST-Elevation myocardial infarction: a systematic review and meta-analysis

Objective: Recent studies have shown that fragmented QRS (fQRS) is associated with unfavourable outcomes in STEMI patients. However, there is controversy amongst studies. We performed a systematic review and meta-analysis to explore the effect of fQRS on reperfusion failure and in-hospital mortality among this population.Methods: We searched the databases of MEDLINE and EMBASE from inception to October 2018. Included studies were published cohort studies of STEMI patients that underwent primary percutaneous coronary intervention (pPCI) and thrombolysis. Data from each study were combined using the random-effects model.Results: Ten studies from January 2011 to October 2018 (2753 patients, 1075 patients with fQRS), were included. The fQRS was associated with higher risk of reperfusion failure in pPCI when defined by ST-segment resolution (OR = 3.08, 95% CI = 1.27-7.46, p-value = .013) but not when defined by TIMI flow grade (pooled OR = 1.45, 95% CI = 0.83-2.54, p-value = .192). In thrombolysis, fQRS was associated with higher risk of reperfusion failure when defined by both ST-segment resolution (pooled OR = 4.35, 95% CI = 1.80-10.49, p-value = .001) and TIMI flow grade (OR = 3.70, 95% CI = 2.10-6.53, p-value < .001). The fQRS was also associated with an increased risk of in-hospital mortality in both pPCI (pooled OR = 4.41, 95% CI = 1.60-12.16, p-value = .004) and thrombolysis (pooled OR = 2.38, 95% CI = 1.06-5.35, p-value = .036).Conclusions: Our meta-analysis demonstrated that fQRS in STEMI patients was associated with reperfusion failure as well as in-hospital mortality.

Prognostic value of fragmented QRS complex in patients with acute myocardial infarction

BACKGROUND

Several factors and risk stratification tools have been studied to determine the prognosis of acute coronary syndrome. Fragmented QRS (fQRS) is a marker of myocardial scar and its prognostic role has recently been demonstrated. The present study aimed to investigate the association between the presence of fQRS in electrocardiogram and the prognosis of ST-segment elevation and non-ST-segment elevation myocardial infarction (STEMI and NSTEMI).

METHODS

A total of 661 patients with myocardial infarction (MI) were enrolled in a retrospective study. Based on the presence of fQRS in admission electrocardiogram, patients were divided into two groups. All patients were followed up for 6 months, and all major adverse cardiovascular events (MACE) were recorded.

RESULTS

The mean age of patients was 61.3 ± 1.2 years, and 71.7% were male. In the acute phase, the detection rates of regional wall motion abnormality and aortic valve insufficiency were higher in positive fQRS compared to negative fQRS group (p = 0.003). The incidence of total MACE was significantly higher in the positive fQRS compared to the negative fQRS group among all patients and in both STEMI and NSTEMI subgroups (p < 0.001). Based on multivariate analysis, the presence of fQRS and hypertension were the strongest predictors of total MACE at 6‑month follow-up (odds ratio [OR] = 5.929; 95% confidence interval [CI] = 3.620-9.709; p < 0.001 and OR = 2.220; 95% CI = 1.390-3.547; p < 0.001, respectively).

CONCLUSION

Regardless of the type of MI, it was found that the presence of fQRS on admission electrocardiogram can be implemented in risk stratification tools in patients with acute MI.

The presence of fragmented QRS may predict the recurrence of nonvalvular atrial fibrillation after successful electrical cardioversion

OBJECTIVE

Atrial fibrillation (AF), the most common cardiac rhythm disorder, affects approximately 2% of the general population and is associated with increased risk of stroke and mortality as well as reduced exercise capacity and quality of life. After restoring normal sinus rhythm, a portion of these patients develops recurrent AF despite optimal medical treatment. In this study, we aimed to assess the relationship between the presence of fragmented QRS (fQRS) and AF recurrence following successful electrical cardioversion (ECV).

MATERIAL AND METHODS

A total of 306 patients with nonvalvular persistent AF achieving restoration of the sinus rhythm after successful ECV were included in this study. After ECV, patients were monitored at least 6 months for recurrence. The patients were divided into two groups according to the presence of fQRS and compared for AF recurrence during follow-up.

RESULTS

Patients were followed up for a mean time of 220 ± 113 days. AF recurred in 119 patients, corresponding to a recurrence rate of 38.8%. AF recurrence was found to be significantly increased in patients with fQRS as compared to those without fQRS (76.4% vs. 23.5%, p < .001). Furthermore, the presence of fQRS was higher in patients with recurrent AF as compared to others (57.1% vs. 11.2%, p < .001). In multiple regression analyses, the presence of fQRS was one of the independent predictors of AF recurrence (hazard ratio: 9.670, 95% CI: 4.714-19.837, p < .001).

CONCLUSION

The presence of fQRS may be associated with the recurrence of AF after successful ECV in persistent nonvalvular AF patients.

Fragmented QRS - Its significance

Fragment QRS (fQRS) complex is a myocardial conduction abnormality that indicates myocardial scar. It is defined as additional notches in the QRS complex. Though initially fQRS was defined in the setting of normal QRS duration (<120 m s), later it has been expanded to include conditions with wide QRS complexes as in bundle branch block, ventricular ectopy and paced rhythm, when more than 2 notches are present. It is an important, yet often overlooked marker of mortality and arrhythmic events in many cardiac diseases. The significance of fQRS lies in the fact that it just requires a surface ECG for its recording and the value of information about the condition of the heart it dispenses based on the clinical setting. We review the role of fQRS in predicting adverse cardiac events in various conditions.

Association of QRS Complex Fragmentation with QT Interval Prolongation in Patients with Ischemic Heart Disease

BACKGROUND

The fragmented QRS complex (FQRS) was found to be associated to malignant ventricular arrhythmias and sudden death in patients with hypertrophic cardiomyopathy and other entities. There is scant data available correlating the presence of FQRS with QT interval prolongation in patients with ischemic heart disease (IHD).

METHODS

A descriptive, retrospective, cross-sectional study was performed in 123 patients with IHD to analyze and correlate the presence of FQRS with QT interval prolongation in the conventional 12-leads electrocardiogram in patients with documented chronic IHD.

RESULTS

There were 62% male patients. The mean age was 63.8±12.6 years. Thirty six (44%) patients had fragmented QRS (64% men and 36% women). The duration of QT and QTc, the mean values were 413±59ms, and 463±67ms, respectively. Of the 36 patients with FQRS, 23 patients have prolongation of the QTc interval, and 13 patients did not present it. Of the 45 patients without FQRS, 21 of them have prolongation of the QTc interval, and 24 patients did not have it. These data resulted in a sensitivity of 52% with a moderate SnNout, a specificity of 65% with moderate SpPin, a positive predictive accuracy of 64%, a negative predictive accuracy of 53%. These data resulted in a prevalence of 54%.

CONCLUSION

the presence of FQRS in the ECG has a moderate sensitivity and specificity, as well as, moderate negative and positive predictive value of the existence of QT interval prolongation in patients with ischemic heart disease.

Fragmented QRS and mortality in patients undergoing percutaneous intervention for ST-elevation myocardial infarction: Systematic review and meta-analysis

BACKGROUND

Fragmented QRS reflects disturbances in the myocardium predisposing the heart to ventricular tachyarrhythmias. Recent studies suggest that fragmented QRS (fQRS) is associated with mortality in ST-elevation myocardial infarction (STEMI) patients who underwent percutaneous coronary intervention (PCI). However, a systematic review and meta-analysis of the literature has not been done. We assessed the association between fQRS and overall mortality in STEMI patients who subsequently underwent PCI by a systematic review and meta-analysis.

METHODS

We comprehensively searched the databases of MEDLINE and EMBASE from inception to September 2017. Studies included in our analysis were published cohort (prospective or retrospective) and case-control studies that compared overall mortality among STEMI patient with and without fQRS who underwent PCI. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian, and Laird to calculate risk ratios and 95% confidence intervals.

RESULTS

Six studies from 2014 to 2017 were included in this meta-analysis involving 2,516 subjects with STEMI who underwent PCI (888 fQRS and 1,628 non-fQRS). Fragmented QRS was associated with overall mortality in STEMI patients who underwent PCI (pooled risk ratio = 3.87; 95% CI 1.96-7.66, I²  = 43%).

CONCLUSION

Fragmented QRS was associated with increased overall mortality up to threefold. Our study suggests that fQRS could be an important tool for risk assessment in STEMI patients who underwent PCI.