Baseline fragmented QRS increases the risk of major arrhythmic events in Brugada syndrome: 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 major arrhythmic events in Brugada syndrome. However, a systematic review and meta‐analysis of the literature has not been done. We assessed the association between fQRS and major arrhythmic events in Brugada syndrome by a systematic review of the literature and a meta‐analysis.

Methods

We comprehensively searched the databases of MEDLINE and EMBASE from inception to May 2017. Included studies were published prospective or retrospective cohort studies that compared major arrhythmic events (ventricular fibrillation, sustained ventricular tachycardia, sudden cardiac arrest, or sudden cardiac death) in Brugada syndrome with fQRS versus normal QRS. 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

Nine studies from January 2012 to May 2017 were included in this meta‐analysis involving 2,360 subjects with Brugada syndrome (550 fQRS and 1,810 non‐fQRS). Fragmented QRS was associated with major arrhythmic events (pooled risk ratio =3.36, 95% confidence interval: 2.09‐5.38, p < .001, I² = 50.9%) as well as fatal arrhythmia (pooled risk ratio =3.09, 95% confidence interval: 1.40‐6.86, p = .005, I² = 69.7%).

Conclusions

Baseline fQRS increased major arrhythmic events up to 3‐fold. Our study suggests that fQRS could be an important tool for risk assessment in patients with Brugada syndrome.

     

碎裂 QRS 波对心肌梗死患者心血管事件的预测价值

碎裂 QRS 波（fragmented QRS complex,fQRS）作为一项新的无创心脏电生理指标,多见于心肌梗死患者。近年来,学者们发现 fQRS 波也见于非缺血性心肌病、致心律失常性右室发育不良型心肌病、布加综合征等疾病中。fQRS 波对心肌梗死的辅助诊断有帮助,且对心肌梗死患者心源性死亡及主要心血管事件有一定的预测作用。它对血管再通治疗的疗效评估亦有重要意义。本文就 fQRS 波在心肌梗死患者预后判断及危险分层中的作用展开论述。     

Use of fragmented QRS in prognosticating clinical deterioration and mortality in pulmonary embolism: A meta‐analysis

Background

Fragmented QRS (fQRS) on electrocardiography is potentially valuable in prognosticating acute pulmonary embolism (PE). ECG is one of the first tests performed in the emergency department, quickly interpretable, noninvasive, inexpensive, and available in remote areas. We aimed to review fQRS's role in PE prognostication.

Methods

We searched MEDLINE, EMBASE, Google Scholar, Web of Science, abstracts, conference proceedings, and reference lists until October 2017. Eligible studies used fQRS to prognosticate patients for the main outcomes of death and clinical deterioration or escalation of therapy. Two authors independently selected studies, with disagreement resolved by consensus. Ad hoc piloted forms were used to extract data and assess risk of bias. We used a random‐effects model to pool relevant data in meta‐analysis with odds ratios (OR) and 95% confidence intervals (CI), while all other data were synthesized qualitatively. Statistical heterogeneity was assessed using the I² index.

Results

We included five studies (1,165 patients). There was complete agreement in study selection. fQRS significantly predicted in‐hospital mortality (OR [95% CI], 2.92 [1.73–4.91]; p < .001), cardiogenic shock (OR [95% CI], 4.71 [1.61–13.70]; p = .005), and total mortality at 2‐year follow‐up (OR [95% CI], 4.42 [2.57–7.60]; p < .001). Adjusted analyses were generally consistent with these results.

Conclusion

Although few studies have explored the current study's question, they showed that fQRS is potentially valuable in PE prognostication. fQRS should be considered as an entry, along with other clinical and ECG findings, in a PE risk score.

     

Prognostic value of global longitudinal strain in hypertrophic cardiomyopathy: A systematic review and meta‐analysis

BackgroundAs previously reported, impairment of left ventricular global longitudinal strain (LVGLS) is associated with myocardial fibrosis, arrhythmias, and heart failure in hypertrophic cardiomyopathy (HCM) patients.HypothesisThis study aimed to estimate the association between LVGLS measured by echocardiography and major adverse cardiovascular events (MACE) in patients with HCM.MethodsPubmed, Embase, Scopus, and Cochrane Library databases were systematically searched for evaluating the difference of LVGLS between MACE and non‐MACE and the relevance of LVGLS and MACE in HCM patients, mean difference (MD), and pooled hazard ratios (HR) with 95% confidence interval (CI) were calculated. Publication bias was detected by funnel plots and Egger''s test, and trim‐and‐fill analysis was employed when publication bias existed.ResultsA total of 13 studies reporting 2441 HCM patients were included in this meta‐analysis. Absolute value of LVGLS was lower in the group of HCM with MACE (MD = 2.74, 95% CI: 2.50–2.99, p < .001; I ² = 0, p = .48). In the pooled unadjusted model, LVGLS was related to MACE (HR = 1.14, 95% CI: 1.06–1.22, p < .05, I ² = 58.4%, p < .01) and there is a mild heterogeneity, and sensitivity analysis showed stable results. In the pooled adjusted model, LVGLS was related to MACE (HR = 1.12, 95% CI: 1.08–1.16, p < .05; I ² = 0%, p = .442). Egger''s tests showed publication bias, and trim‐and‐fill analysis was applied, with final results similar to the previous and still statistically significant.ConclusionThe meta‐analysis suggested that impaired LVGLS was associated with poor prognosis in HCM patients.     

健康成年人群和肥厚型心肌病患者碎裂QRS波群的分布规律与特征

目的：比较健康成年人群和肥厚型心肌病患者碎裂QRS波群（fQRS）的检出率、分布规律与特征。方法：前瞻性连续入选1500例无症状的健康体检者,同时回顾性入选经心脏核磁共振检查确诊的肥厚型心肌病患者91例,年龄范围均在18~65岁。记录并分析所有患者的常规12导联心电图。fQRS的定义为至少2个连续导联的QRS波群存在≥2个R波或者R波的波顶或S波的波谷出现顿挫波。结果：健康成人和肥厚型心肌病患者分别有76（5.1%）和19例（20.9%）检出fQRS（P=0.001）,fQRS平均导联数目无明显差异（2.3±0.7 vs 2.1±0.3,P=0.082）。健康成人中86.8%（66/76）的fQRS分布于下壁导联,另外13.2%（10/76）分布于胸前导联,而肥厚型心肌病患者的fQRS主要分布在下壁导联（10/19,52.6%）,其次分布在前壁导联（6/19,31.8%）以及侧壁导联（3/19,15.8%）（与健康成人相比,P<0.001）。与肥厚型心肌病患者的fQRS相比,健康成人的fQRS的平均额面心电轴更偏左（27.9±30.7°vs 45.5±63.0°,P=0.024）。结论：肥厚型心肌病患者fQRS的检出率高于健康成年人群。与肥厚型心肌病患者的fQRS相比,见于健康成人的fQRS的分布范围更加集中,主要分布于下壁导联,而且后者的额面心电轴更加偏左。     

心电图碎片状QRS波群与心血管事件发生的相关性研究

目的探讨心电图碎片状QRS复合波（fQRs）与心血管事件发生的相关性。方法随机抽取1000份我院心血管内科住院患者的12导联平静心电图,排除存在束支传导阻滞或起搏心律者,剩余939份心电图对应的939例患者为研究对象,按照心电图中是否存在fQRs波分成2组,研究两组患者在性别、年龄、心血管事件发生率等方面差异是否具有统计学意义。结果心电图出现fQRs波组患者冠心病、心肌缺血的总发生率为19．6％,心肌梗死总发生率为10．5％,左心室肥厚发生率为34．7％,相对正常者占35．2％;心电图无fORs波出现组患者冠心病、心肌缺血的总发生率为8．2％,心肌梗死发生率为6．5％,左心室肥厚发生率为12．9％,相对正常者占72．4％。经两样本x2检验,P〈0．01,两组心血管事件发生情况差异有统计学意义。结论心电图中出现fQRs波患者心血管事件的发生率较心电图无fQRs波改变者显著升高（P〈0．01）。碎片状QRS波群的出现能在一定程度上提示心血管事件的发生。     

The value of fragmented QRS in predicting the prognosis of chronic total occlusion patients with myocardial infarction history undergoing percutaneous coronary intervention: A 24‐months follow‐up study

BackgroundFragmented QRS (fQRS) is a marker of local myocardial scar. This study aimed to analyze the relationship between fQRS and coronary collateral circulation (CCC) and evaluate the predictive value of fQRS for long‐term clinical outcomes among patients with chronic total occlusion (CTO) and prior myocardial infarction (MI) who underwent percutaneous coronary intervention (PCI).MethodsA total of 862 patients with a definite history of MI who had one CTO coronary artery and underwent PCI between 2013 and 2018 were continuously analyzed. Patients were divided into group A (no Q wave and fQRS, n = 206), group B (fQRS, n = 265), group C (Q wave, n = 391). All patients were followed up for 2 years.ResultsThe incidence rate of major adverse cardiovascular events (MACE) in group B was significantly lower than in group C (group B vs. C: 7.2% vs. 11.3%, P = 0.043). The percentage of good CCC was 94.2%, 88.3%, and 82.9% in group A, B, and C (p < .001), respectively. The improvement of cardiac function in group B and A were more significant than in group C. Multivariate Cox regression analysis showed fQRS was an independent protective factor of MACE after PCI within 2 years in CTO patients with prior MI (RR = 0.668, 95% CI [0.422–0.917], p = .001).ConclusionfQRS is an independent protective factor of prognosis in patients with prior MI and one CTO vessel who underwent PCI, presenting with a higher rate of good CCC, less occurrence of MACE, and better heart function than in Q wave patients.     

碎裂 QRS 波与急性心肌梗死患者预后的关系研究

目的：探讨碎裂 QRS （fragmented QRS，fQRS）波与急性心肌梗死（acute myocardial infarction，AMI）预后的关系。方法入选287例 AMI 患者，根据心电图是否存在 fQRS 波分为fQRS 组和无 fQRS 组，采集相关临床资料。随访1～36个月的心源性死亡和非致死性心脏事件（再梗死、持续室性心动过速、室颤、心源性休克、严重心力衰竭）发生情况，用 Kaplan Meier法和 Cox 比例风险模型比较生存率、发生率和风险度。结果① fQRS 组与无 fQRS 组3年内非致死性心脏事件发生率分别是28．9％和12．2％（χ2＝13．303，P ＝0．000）。在校正了年龄等混杂因素的影响后，fQRS 组患者发生非致死性心脏事件的风险度（HR）为2．642，Wald ＝11．593，P ＝0．001。② fQRS 组1、2、3年累计生存率分别为93．1％、91．4％和88．6％，无 fQRS组1、2、3年累计生存率分别为98．2％、97．0％和95．7％（χ2＝5．276，P ＝0．022）。在调整了患者年龄等因素的作用后，fQRS 组患者发生心源性死亡的 HR 为2．674，Wald ＝4．371，P ＝0．037。结论fQRS 波是评估 AMI 后患者预后的一项新的无创心电指标。     

Usefulness of fragmented QRS in hypertensive patients in the absence of left ventricular hypertrophy

In the absence of left ventricular hypertrophy, importance of fragmented QRS complex (fQRS) in individuals with hypertension is unknown. The authors aimed to evaluate the relationship between blood pressure levels and fQRS in the absence of left ventricular hypertrophy. A total of 548 never‐treated patients who underwent 24‐hour ambulatory blood pressure monitoring were enrolled. The frequency of fQRS was significantly higher in patients with hypertension than normotension (36.4% vs 17.6%, P<.05). Multivariate logistic regression analysis revealed that systolic blood pressure is significantly associated with presence of fQRS on electrocardiography (odds ratio, 0.931; 95% CI, 0.910–0.9521 [P<.001]) even after adjusting for other confounding factors. Receiver operating characteristic analysis revealed a cutoff value of 147.65 mm Hg for systolic blood pressure to predict presence of fQRS (sensitivity: 51%, specificity: 99%, area under the curve=0.764; 95% CI, 0.717–0.811 [P<.001]). fQRS may be a sign of increased blood pressure and may predict higher fibrotic burden in patients with hypertension.     

碎裂QRS波与肥厚型心肌病患者心肌纤维化/瘢痕的关系

目的 评价常规12导联心电图检出的碎裂QRS波(fragmented QRS complex,fQRS)与肥厚型心肌病患者心肌纤维化/瘢痕的关系.方法 91例肥厚型心肌病患者,通过心脏磁共振检查检出心肌纤维化/瘢痕.记录所有患者的常规12导联心电图,判读是否存在fQRS.结果 9l例患者中,58例(63.7％)经由心脏磁共振检出了延迟增强(late gadolinium enhancement,LGE),其中19例(20.9％)心电图检出fQRS.LGE阳性患者的fQRS检出率显著高于LGE阴性患者(31.0％对3.0％,P=0.002).在检出fQRS的19例患者中,18例(94.7％)检出了LGE.在检出LGE的患者中,fQRS阳性患者较fQRS阴性患者的LGE节段分布更为广泛(2.8±1.6对2.0±1.1,P=0.035).fQRS在肥厚型心肌病患者中检出心肌纤维化/瘢痕的敏感性和特异性分别为31.0％和97.0％.结论 常规12导联心电图上检出的fQRS是肥厚型心肌病患者存在心肌纤维化/瘢痕的特异性指标,但其敏感性有限.     

Noncardiac surgery and the risk of death and other cardiovascular events in patients with hypertrophic cardiomyopathy

BACKGROUND: There is a paucity of reports evaluating the perioperative risk of noncardiac surgery in patients with hypertrophic cardiomyopathy (HCM). HYPOTHESIS: The study was undertaken to evaluate the incidence of acute myocardial infarction (MI) and all-cause inhospital mortality following noncardiac surgery in patients with HCM. METHODS: We searched the National Hospital Discharge Survey database for patients with a diagnosis of HCM who had undergone noncardiac surgery. Cases were matched by age, gender, and year of surgery. Death or acute MI were used as endpoints for analysis. RESULTS: From 1996 to 2002, 227 patients with HCM were matched with 554 controls (representing national estimates of 25,874 HCM and 50,326 controls patients). Patients with HCM were more likely than controls to have a history of atrial fibrillation (22.7 vs. 10.6%, p < 0.001) and of congestive heart failure (CHF) (24.2 vs. 14.1%, p < 0.001). The in-hospital incidence of death or MI was higher in patients with HCM than in controls (6.7 vs. 2.5%, p < 0.001 for death and 2.2 vs. 0.3%, p < 0.001 for MI). After correcting for age, gender, race, presence of hypertension, diabetes mellitus, history of coronary artery-disease, history of CHF, atrial fibrillation, and ventricular arrhythmias in a multivariate binary logistic regression model, the presence of HCM increased the odds of death by 61% (odds ratio [OR] = 1.61, 95% confidence interval [CI] 1.46-1.77, p < 0.001), and almost tripled the odds of the combined endpoint of death or MI (OR = 2.82, 95% CI 2.59-3.07, p < 0.001). CONCLUSION: The presence of HCM significantly increases the risk of death and MI associated with noncardiac surgery. Patients with HCM undergoing elective procedures may require more careful preoperative assessment and perioperative monitoring. The impact of the severity of HCM on outcomes of noncardiac surgery needs further study.