The decisive role of cardiovascular MRI delayed hyperenhancement (DHE) pattern for risk stratification for dilated cardiomyopathy

Introduction

Risk stratification in dilated cardiomyopathy (CMX) patients with advanced heart failure remains a growing clinical challenge. A simple manner to non-invasively risk stratify this difficult cohort would have obvious advantages.

Hypothesis

Utilizing cardiovascular MRI (CMR), recently demonstrated to identify abnormal myocardial substrate, typically infarct or more recently infiltrative pathology via the delayed hyperenhancement technique (DHE), we hypothesize that +DHE will represent an adverse prognosis as defined by need for urgent cardiac transplantation (TX), LVAD or death in a dilated cardiomyopathy patients.

Methods

Over 24 consecutive months, 13 patients with a dilated CMX and NYHA class III-IV heart failure underwent standard 3D CMR (1.5 T GE, Excite, Milwaukee, WI) to interrogate the pattern, distribution and extent of DHE (MultiHance, Bracco Diagnostics, Princeton, N J, USA). Patients were categorized into: 1) + DHE/+midwall Stripe 2) +DHE/-midwall Stripe and 3) -DHE/-Stripe. LVAD, Tx need, major adverse clinical events (MACE) and event free survival were evaluated over the next 6 months.

Results

All patients were alive at 6 months for folow-up while 5 required Tx. All pts completed the CMR exam in 50 ± 10 minutes. Of 11/13 pts (85%) with +DHE, 9/11 pts (82%) had +Stripe and 2/13 pts were -DHE/-Stripe. DHE/Stripe categorization positively strongly correlated with NYHA class (r = 0.59, p < 0.05) while only weakly correlating with 3D LVEF (r = 0.14, p = ns) and EDV (r = 0.05, p = ns). However, DHE/Stripe categorization strongly predicted the need for LVAD and/or urgent Tx surgery over the ensuing 6 months (X² = 5, p < 0.05). Specifically, all 5 pts requiring LVAD and/or urgent Tx by 6 months had +DHE/+Stripe while no -DHE/-Stripe pts experienced the need for LVAD or urgent Tx. Similarly, a +DHE/+Stripe strongly predicted MACE (X² = 8, p < 0.005). Any +DHE pt with + or -Stripe, in general, predicted a more egregious course, meeting a MACE, worsening LVEF, or non-improved/worsening NYHA class. No -DHE/-Stripe patient had a major adverse clinical event, see Table 1.

Table 1

Conclusion

CMX patients with advanced heart failure require an improved risk stratification policy. We believe this observation represents the first attempt to risk stratfiy systematically for those with a dilated CMX. Specifically, a simple observation of the binary nature of DHE/Stripe predicated early morbidity and mortality. Herein, using standard CMR, the presence of +DHE/+Stripe is highly predictive of LVAD and Tx need over the ensuing 6 months. Those +DHE/-Stripe patients have intermediate risk but no LVAD/Tx use, while those -DHE/-Stripe have a good prognosis. Thus, incorporating this approach into routine clinical practice may help manage CMX patients more expectantly and effectively.