High signal intensity on T2 weighted cardiac magnetic resonance imaging in hypertrophic cardiomyopathy: Is it a marker of myocardial injury?

Background

Previous studies observed the phenomenon of high signal intensity on T2 -weighted image of cardiac magnetic resonance imaging (CMR) in hypertrophic cardiomyopathy(HCM). However, the underlying histopathologic mechanism is unclear. Elevated cardiac troponin can be detected in some HCM patients. A reasonable hypothesis is that myocardial T2-high signals is a potential marker of myocaridal injury in HCM. We sought to investigate the association between cardiac troponin and the extent of T2-high signals in HCM patients.

Methods

Forty-four HCM patients underwent 3.0T CMR scanning. On T2-weighted images, the number of segments with high-signal intensity(myocardium to skeletal muscle signal intensity ratio>2)and the percentage of high-signal area (>2 SD above remote tissue) were measured in 16 myocardial segments along the LV mid-myocardial circumference on 3 short-axis images. The level of high sensitivity cardiac troponin T(hs-cTnT) was also assessed.

Results

Myocardial T2-high signals were indentified in 33(75%)patients and 144(20.5%) segments.Elevated hs-cTnT was observed in 28(63.6%)patients.Cochran-Armitage test showed a statistically significant trend of increasing level of hs-cTnT with elevating number of segments with myocardial T2-high signal (p=0.002).Then,Pearson^,s test showed the percentage of myocardium with T2-high signal significantly associated with the hs-cTnT level(r=0.388,P=0.009)

Conclusions

Myocardial T2-high signals can be considered as a marker of myocardial injury in HCM patients.

Figure 1

The relationship between the percentage of myocardium with T2-high signal and the level of high sensitivity cardiac troponin T(hs-cTnT)in patients with hypertrophic cardiomyopathy.

Table 1 Cardiac magnetic resonance characteristics of patients with HCM