What is the clinical evidence from this study?

Study design: Cross-Sectional. Population: Hypertrophic Cardiomyopathy (n=65). Intervention: Myocardial hyperintensity on T2-weighted short-tau inversion recovery (HyT2) vs. Absence of HyT2. Primary outcome: Non-sustained ventricular tachycardia (NSVT) on 24-h ECG recording (OR 165, 95% CI 11-2455, p=<0.001).

October 30, 2014Open Access

Abnormal T2-STIR Magnetic Resonance in Hypertrophic Cardiomyopathy: A Marker of Advanced Disease and Electrical Myocardial Instability

Q: What are the key findings of this study?

In patients with hypertrophic cardiomyopathy, the presence of myocardial hyperintensity on T2-STIR magnetic resonance was strongly associated with non-sustained ventricular tachycardia (OR 165).

Key Result

In patients with hypertrophic cardiomyopathy, the presence of myocardial hyperintensity on T2-STIR magnetic resonance was strongly associated with non-sustained ventricular tachycardia (OR 165).

Study Design

Type

Cross-Sectional (n=65)

Multicenter

Yes

Structured PICO

Does myocardial hyperintensity on T2-STIR CMR associate with ventricular electrical instability and advanced disease in patients with hypertrophic cardiomyopathy?

Population

65 patients with hypertrophic cardiomyopathy who underwent clinical examination, 24-hour ECG recording, and cardiac magnetic resonance imaging to evaluate markers of ventricular electrical instability.

Exposure

Myocardial hyperintensity on T2-weighted short-tau inversion recovery (STIR) (HyT2) cardiac magnetic resonance (CMR)

Comparator

Absence of HyT2 on CMR

Outcome

Relationship between HyT2 and markers of ventricular electrical instability (non-sustained ventricular tachycardia on 24-h ECG) and clinical/CMR parameterssurrogate

In patients with hypertrophic cardiomyopathy, myocardial hyperintensity on T2-STIR CMR is strongly associated with non-sustained ventricular tachycardia and advanced disease features.

Main Result

Odds Ratio: 165 (95% CI 11–2455)

Absolute Event Rate: 77.8% vs 2.6%

p-value: p=<0.001

Limitations

HyT2 may be detected in conditions other than ischemia and inflammation, and the etiology of HyT2 in HCM remains unclear.
The mechanism underlying the association between HyT2 and ventricular arrhythmias remains unclear.
The assumption that HyT2 in HCM is a sign of acute, transient myocardial damage was based on other cardiac diseases, lacking serial CMR examinations to confirm reversibility.

Abstract

BACKGROUND: Myocardial hyperintensity on T2-weighted short-tau inversion recovery (STIR) (HyT2) cardiac magnetic resonance (CMR) images has been demonstrated in patients with hypertrophic cardiomyopathy (HCM) and is considered a sign of acute damage. The aim of the current study was to evaluate the relationship between HyT2 and both a) markers of ventricular electrical instability and b) clinical and CMR parameters. METHODS: Sixty-five patients underwent a thorough clinical examination, consisting of 24-h ECG recording and CMR examination including functional evaluation, T2-STIR images and late gadolinium enhancement (LGE). RESULTS: HyT2 was detected in 27 patients (42%), and subjects with HyT2 showed a greater left ventricle (LV) mass index (p<0.001), lower LV ejection fraction (p = 0.05) and greater extent of LGE (p<0.001) compared to those without HyT2. Twenty-two subjects (34%) presented non-sustained ventricular tachycardia (NSVT) on the 24-h ECG recording, 21 (95%) of whom exhibited HyT2. Based on the logistic regression analysis, HyT2 (odds ratio OR: 165, 95% CI 11-2455, p<0.001) and LGE extent (1.1, 1.0-1.3, p<0.001) served as independent predictors of NSVT, while the presence of LGE was not associated with NSVT occurrence (p = 0.49). The presence of HyT2 was associated with lower heart rate variability (p = 0.006) and a higher number of arrhythmic risk factors (p<0.001). CONCLUSIONS: In HCM patients, HyT2 upon CMR examination is associated with more advanced disease and increased arrhythmic burden.

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