Assessment of the relationship between the ambulatory electrocardiography-based micro T wave alternans and the predicted risk score of sudden cardiac death at five years in patients with hypertrophic cardiomyopathy

Q: What are the key findings of this study?

Positive microvolt T-wave alternans on ambulatory ECG independently predicted a high 5-year sudden cardiac death risk score in hypertrophic cardiomyopathy patients.

Q: What is the clinical evidence from this study?

Study design: Observational. Population: Hypertrophic cardiomyopathy (n=117). Intervention: Positive microvolt T-wave alternans (MTWA >=65 uV) on ambulatory Holter ECG vs. Negative microvolt T-wave alternans (MTWA 6%) (OR 79.741, 95% CI 13.685-464.687, p=<0.001).

Q: What does this research mean for the field?

The presence of micro T-wave alternans on ambulatory electrocardiography is an independent predictor of high 5-year sudden cardiac death risk in patients with hypertrophic cardiomyopathy. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Q: What question did this study set out to answer?

To evaluate the relationship between micro T-wave alternans detected on ambulatory electrocardiography and predicted five-year sudden cardiac death risk in patients with hypertrophic cardiomyopathy.

Sinem Özyılmaz

doi:10.14744/anatoljcardiol.2018.15945

January 1, 2018The Anatolian Journal of CardiologyOpen Access

Assessment of the relationship between the ambulatory electrocardiography-based micro T wave alternans and the predicted risk score of sudden cardiac death at five years in patients with hypertrophic cardiomyopathy

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Key result

Positive MTWA on ambulatory ECG linked to ~80-fold higher risk of high-risk HCM status.

OR 79.741
95% CI 13.685-464.687
P<0.001
n=117

Figures

Why the study?

Does the presence of micro T-wave alternans on ambulatory ECG predict a higher 5-year risk of sudden cardiac death in patients with hypertrophic cardiomyopathy?

Key Points

To evaluate the relationship between micro T-wave alternans detected on ambulatory electrocardiography and predicted five-year sudden cardiac death risk in patients with hypertrophic cardiomyopathy.
Prospective observational study of 117 consecutive patients with hypertrophic cardiomyopathy.
Patients were grouped by the presence of micro T-wave alternans on 24-hour ambulatory Holter monitoring into MTWA (+) (n=44) and MTWA (-) (n=73) cohorts.
Clinical, echocardiographic, and arrhythmic outcomes were compared, followed by receiver operating characteristic and multivariate regression analyses.
Predicted five-year sudden cardiac death risk was significantly higher in MTWA (+) patients than MTWA (-) patients (9.1±4.3% vs 3.6±2.3%, p<0.001), with 82% versus 8% categorized as high risk (>6%, p<0.001).
MTWA (+) independently predicted high HCM Risk-SCD risk on multivariate analysis (OR: 79.741, 95% CI: 13.685–464.687, p<0.001).
An HCM Risk-SCD cutoff >4.9% demonstrated an area under the curve of 0.932 (95% CI: 0.887–0.978, p<0.001), yielding 93.2% sensitivity and 84.5% specificity for MTWA (+).

Study Design

Type

Observational (n=117)

Multicenter

Yes

Structured PICO

Does the presence of micro T-wave alternans on ambulatory ECG predict a higher 5-year risk of sudden cardiac death in patients with hypertrophic cardiomyopathy?

P

Population

117 adults (mean age 46.6 years, 39.4% female) with hypertrophic cardiomyopathy evaluated for primary prevention ICD, free of prior cardiac arrest or sustained VT, followed for a mean of 31.7 months.

E

Exposure

Presence of micro T-wave alternans (MTWA) on ambulatory (Holter) electrocardiography

C

Comparator

Absence of micro T-wave alternans (MTWA) on ambulatory (Holter) electrocardiography

O

Outcome

Predicted 5-year risk of sudden cardiac death (HCM Risk-SCD)surrogate

Main Result

Odds Ratio: 79.741 (95% CI 13.685–464.687)

Absolute Event Rate: 82% vs 8%

p-value: p=<0.001

The presence of micro T-wave alternans on ambulatory ECG is an independent indicator of high predicted 5-year risk of sudden cardiac death in patients with hypertrophic cardiomyopathy.

Limitations

Not an epidemiological or randomized study
Relatively small sample size (preliminary study)
Mean follow-up period was not long enough
Quantitative late gadolinium enhancement (LGE) assessment with CMR was not performed in all patients
Genetic tests and Anderson-Fabry screening were only performed in a subset of patients
Some patients were taking anti-arrhythmic drugs during TWA measurement rather than being in a drug-free state
TWA was not characterized by the quantitative model

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Implication

May refine SCD risk assessment in HCM; leaves open prospective validation before any practice change.

Abstract

OBJECTIVE: Micro T-wave alternans (MTWA) has been associated with poor arrhythmic prognosis in various cardiac disorders. The aim of this study was to assess the relationship between the presence of MTWA and the predicted 5-year risk of sudden cardiac death (HCM Risk-SCD) among patients with hypertrophic cardiomyopathy (HCM). METHODS: A total of 117 consecutive HCM patients were included in this prospective observational study. Patients were divided into two groups, according to the presence [MTWA (+) group (n=44)] or absence [MTWA (-) group (n=73)] of MTWA on ambulatory (Holter) electrocardiography. RESULTS: The risk of HCM Risk-SCD (%), the rate of high-risk patients (HCM Risk-ECG >6%), the requirement for cardiopulmonary resuscitation, and implanted cardioverter defibrillator therapy, the percentage of some clinical, echocardiographic, and Holter findings were all statistically higher in the MTWA (+) group than in the MTWA (-) group (all p<0.05). Both in the univariate and multivariate analyses, T-wave alternans (+) and the New York Heart Association's functional classification assigned that the HCM Risk-SCD is an independent predictor of high risk. In the receiver operating characteristic curve analysis, the HCM Risk-SCD >4.9% was identified as an effective cutoff point in the MTWA (+) for HCM. The HCM Risk-SCD value of more than 4.9 yielded a sensitivity of 93.2% and a specificity of 84.5%. CONCLUSION: The presence of the MTWA on ambulatory electrocardiogram seems to be significantly associated with increasing percentages of the predicted HCM Risk-SCD score in patients with HCM. The MTWA was determined as an independent high-risk indicator for HCM Risk-SCD.

Discussion

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Cite This Study

Sinem Özyılmaz (2018) conducted an observational in Hypertrophic cardiomyopathy (n=117). Positive microvolt T-wave alternans (MTWA >=65 uV) on ambulatory Holter ECG vs. Negative microvolt T-wave alternans (MTWA <65 uV) was evaluated on High predicted 5-year risk of sudden cardiac death (HCM Risk-SCD >6%) (OR 79.741, 95% CI 13.685-464.687, p=<0.001). Positive microvolt T-wave alternans on ambulatory ECG independently predicted a high 5-year sudden cardiac death risk score in hypertrophic cardiomyopathy patients.

synapsesocial.com/papers/6a7c5144e7cf49620a26b8c7 https://doi.org/10.14744/anatoljcardiol.2018.15945

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Assessment of the relationship between the ambulatory electrocardiography-based micro T wave alternans and the predicted risk score of sudden cardiac death at five years in patients with hypertrophic cardiomyopathy

Figures

Key Points

Study Design

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

Assessment of the relationship between the ambulatory electrocardiography-based micro T wave alternans and the predicted risk score of sudden cardiac death at five years in patients with hypertrophic cardiomyopathy

Figures

Key Points

Study Design

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

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