Skip to content

Advertisement

  • Oral presentation
  • Open Access

Fragmented QRS complex and late gadolinium enhancement characterization of unrecognized myocardial scar provided complementary prognosis of cardiac death in patients with suspected coronary artery disease

  • 1,
  • 1,
  • 1,
  • 1,
  • 1,
  • 1,
  • 1,
  • 1 and
  • 1
Journal of Cardiovascular Magnetic Resonance201012(Suppl 1):O5

https://doi.org/10.1186/1532-429X-12-S1-O5

Published: 21 January 2010

Keywords

  • Coronary Artery Disease
  • Leave Ventricular Ejection Fraction
  • Cardiovascular Magnetic Resonance
  • Cardiac Death
  • Late Gadolinium Enhancement

Introduction

Fragmentation of the QRS complex (FQRS) on the resting electrocardiogram has been shown to be associated with post-infarct arrhythmogenesis and increased incidence of hard cardiac events. Late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) imaging can detect subendocardial unrecognized myocardial infarction which has been shown to indicate high risk for cardiac death.

Purpose

This study sought to determine if FQRS and evidence of unrecognized myocardial scar by LGE, provide similar or incremental prognostic information in patients with suspected but no prior history of coronary artery disease (CAD).

Methods

The study was conducted on 331 patients (176 men and 155 women) referred for CMR assessment for evidence of CAD. Electrocardiograms were performed, on average, 1.6 ± 5 days before the CMR exam. FQRS was assessed according to established criteria. The patients were followed for a median duration of 3.27 years to monitor cardiac events.

Results

The patients have a mean age of 54.7 years. 83% of patients were diabetic, 59% had hypercholesterolemia and 54% had hypertension. The mean left ventricular ejection fraction (LVEF) was 60%. During the follow-up period, there were 16 cardiovascular deaths (4.9%). Baseline FQRS was present in 74 patients: 46 patients had FQRS in the inferior leads (II, III, aVF), 21 had FQRS in the anterior leads (V1-V6) and 7 patients had FQRS in the anterior and inferior leads. No patient had FQRS in the lateral leads (I, aVL, V5-6). LGE was present in 36 patients (12%). By univariable analysis (Table 1), LGE and FQRS in the anterior leads portended to a 10-fold (Hazard Ratio, HR = 9.59, p < 0.0001) and to a 5-fold (HR = 4.49, p = 0.005) increase in hazards to cardiac death, respectively. By multivariable analysis adjusting for age and LVEF, both FQRS in the anterior leads (HR = 13.1, p < 0.001) and LGE (HR = 14.6, p < 0.001) maintained strong and significant adjusted association with cardiac death.
Table 1

Hazard ratio for cardiac death by univariable analysis

Variable

HR

95% CI

P-value

Age

1.05

[1.01, 1.09]

0.015

Female gender

0.77

[0.28, 2.12]

0.611

Hypertension

1.84

[0.65, 5.16]

0.249

Diabetes

2.01

[0.68, 5.89]

0.205

Dyslipidemia

2.78

[0.95, 8.14]

0.062

LVEF

0.95

[0.93, 0.98]

0.002

LGE

9.59

[3.47, 26.53]

<0.001

FQRS-anterior leads

4.49

[1.56, 12.94]

0.0005

FQRS-lateral leads

NA

NA

NA

FQRS-inferior leads

0.67

[0.15, 2.94]

0.595

FQRS-any leads

1.84

[0.67, 5.08]

0.238

Note. HR = hazard ration, CI = confidence interval

Conclusion

In patients with clinical suspicion and risk factors for CAD, FQRS and unrecognized myocardial scar detected by LGE provide robust and complementary prognosis to cardiac death. Incorporation of these non-invasive techniques in risk stratification algorithms warrants further prospective study.

Authors’ Affiliations

(1)
Brigham and Women's Hospital. Harvard Medical School, Boston, USA

Copyright

© Hsiao et al; licensee BioMed Central Ltd. 2010

This article is published under license to BioMed Central Ltd.

Advertisement