Diagnostic accuracy of a 2D left ventricle hypertrophy score for familial hypertrophic cardiomyopathy

Use of a highly-sensitive cardiac troponin I assay in a screening population for hypertrophic cardiomyopathy: a case-referent study

Background

Hypertrophic cardiomyopathy (HCM) is a genetic condition, and relatives of affected persons may be at risk. Cardiac troponin biomarkers have previously been shown to be elevated in HCM. This study examines the new highly-sensitive cardiac troponin I (hsTnI) assay in a HCM screening population.

Methods

Nested case–control study of consecutive HCM sufferers and their relatives recruited from May 2010 to September 2011. After informed consent, participants provided venous blood samples and clinical and echocardiographic features were recorded. Associations between the natural log (ln) of the contemporary troponin I (cTnI) and hsTnI assays and markers of cardiac hypertrophy were examined. Multiple regression models were fitted to examine the predictive ability of hsTnI for borderline or definite HCM.

Results

Of 107 patients, 24 had borderline and 19 had definite changes of HCM. Both TnI assays showed significant, positive correlations with measures of cardiac muscle mass. After age and sex adjustment, the area under the receiver operator characteristic (AUROC) curve for the outcome of HCM was 0.78, 95% CI [0.65, 0.90], for ln(hsTnI), and 0.66, 95% CI [0.51, 0.82], for ln(cTnI) (p=0.11). Including the hsTnI assay in a multiple-adjusted “screening” model for HCM resulted in a non-significant improvement in both the AUROC and integrated discrimination index.

Conclusions

Both cTnI and hsTnI show a graded, positive association with measures of cardiac muscle mass in persons at risk of HCM. Further studies will be required to evaluate the utility of these assays in ECG- and symptom-based identification of HCM in at-risk families.

Sudden cardiac death in young athletes: preparticipation screening for underlying cardiovascular abnormalities and approaches to prevention

The study of sudden cardiac death (SCD) in athletes has received more interest in the medical and lay press over the past few years. Professional athletes represent ideals of fitness and health, and the sudden death of prominent athletes can come as a shock. Underlying occult cardiovascular disorders are the most common cause of SCD in athletes. Unfortunately, because these disorders rarely present clinically, their initial manifestation is often a fatal event. Due to this, much attention has turned to both primary and secondary prevention. Primary prevention includes preparticipation screening and secondary prevention includes having automatic external defibrillators available at sporting events. This article summarizes the most common causes of athletic-related cardiac arrest and evaluates the screening methods used to screen for these conditions. The general sentiment is that we need to more effectively identify athletes who are at risk for SCD, but how to do so using an efficient screening system and in a cost-effective manner have not been determined.

Echocardiography in patients with hypertrophic cardiomyopathy: usefulness of old and new techniques in the diagnosis and pathophysiological assessment

Hypertrophic cardiomyopathy (HCM) is one of the most common inherited cardiomyopathy. The identification of patients with HCM is sometimes still a challenge. Moreover, the pathophysiology of the disease is complex because of left ventricular hyper-contractile state, diastolic dysfunction, ischemia and obstruction which can be coexistent in the same patient. In this review, we discuss the current and emerging echocardiographic methodology that can help physicians in the correct diagnostic and pathophysiological assessment of patients with HCM.

Identifying modifier genes of monogenic disease: strategies and difficulties

Substantial clinical variability is observed in many Mendelian diseases, so that patients with the same mutation may develop a very severe form of disease, a mild form or show no symptoms at all. Among the factors that may explain these differences in disease expression are modifier genes. In this paper, we review the different strategies that can be used to identify modifier genes and explain their advantages and limitations. We focus mainly on the statistical aspects but illustrate our points with a variety of examples from the literature.

Prevalence and characteristics of left ventricular outflow tract obstruction in Tako-Tsubo syndrome

BACKGROUND AND OBJECTIVE

Tako-Tsubo syndrome is a clinical entity mimicking acute coronary syndrome (ACS). Left ventricular outflow tract (LVOT) obstruction may occur in Tako-Tsubo syndrome. The aim of this study was to determine the prevalence and features of LVOT obstruction in Tako-Tsubo syndrome in a population presenting with ACS.

METHODS

This study included consecutive patients admitted to 2 catheterization laboratories for suspected ACS. All patients underwent echocardiography, coronary arteriography, and left ventricular angiography if no significant coronary lesions were found.

RESULTS

Among 10,366 patients referred for coronary angiography, the study population consisted of 3,909 patients with suspected ACS. Thirty-two patients (mean age 71 +/- 13 years old) presented with Tako-Tsubo syndrome, resulting in a prevalence of 0.8% in our population of ACS and 5% of patients without significant coronary lesions. Eight women (mean age 81 +/- 4 years old, P = .01) exhibited LVOT obstruction, a prevalence of 25% among Tako-Tsubo syndrome cases. All patients with intraventricular pressure gradient had systolic anterior motion of the mitral valve and septal bulge. Prevalence of septal bulge was 100% in patients with Tako-Tsubo syndrome and LVOT obstruction versus 29% in patients without LVOT obstruction (P = .002). Mean degree of mitral regurgitation was 2.1 +/- 0.7 in cases of LVOT obstruction versus 0.9 +/- 0.7 in patients without LVOT (P = .0003) and significantly decreased during follow-up (1 +/- 0.8, P = .002). Recovery of left ventricular ejection fraction was similar in patients with and without LVOT obstruction (P = .58).

CONCLUSIONS

The present study demonstrates that the prevalence of LVOT obstruction in Tako-Tsubo syndrome is high, with specific characteristics as compared with patients without LVOT obstruction. Echocardiography should be systematically performed for all patients presenting with Tako-Tsubo syndrome for the detection of LVOT obstruction.

Noninvasive cardiac imaging in patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy and the most common cause of cardiac death in young athletes in the U.S. Noninvasive imaging plays an important role in detecting the disease, understanding its pathophysiology, and selecting as well as guiding appropriate therapy. In this review, we discuss the existing methodology with emphasis on current and emerging clinical applications in patients with HCM.