Prognostic Power of Quantitative Assessment of Functional Mitral Regurgitation and Myocardial Scar Quantification by Cardiac Magnetic Resonance

BACKGROUND

The severity classification of functional mitral regurgitation (FMR) remains controversial despite adverse prognosis and rapidly evolving interventions. Furthermore, it is unclear if quantitative assessment with cardiac magnetic resonance can provide incremental risk stratification for patients with ischemic cardiomyopathy (ICM) or non-ICM (NICM) in terms of FMR and late gadolinium enhancement (LGE). We evaluated the impact of quantitative cardiac magnetic resonance parameters on event-free survival separately for ICM and NICM, to assess prognostic FMR thresholds and interactions with LGE quantification.

METHODS

Patients (n=1414) undergoing cardiac magnetic resonance for cardiomyopathy (ejection fraction<50%) assessment from April 1, 2001 to December 31, 2017 were evaluated. The primary end point was all-cause death, heart transplant, or left ventricular assist device implantation during follow-up. Multivariable Cox analyses were conducted to determine the impact of FMR, LGE, and their interactions with event-free survival.

RESULTS

There were 510 primary end points, 395/782 (50.5%) in ICM and 114/632 (18.0%) in NICM. Mitral regurgitation-fraction per 5% increase was independently associated with the primary end point, hazards ratios (95% CIs) of 1.04 (1.01-1.07; P=0.034) in ICM and 1.09 (1.02-1.16; P=0.011) in NICM. Optimal mitral regurgitation-fraction threshold for moderate and severe FMR were ≥20% and ≥35%, respectively, in both ICM and NICM, based on the prediction of the primary outcome. Similarly, optimal LGE thresholds were ≥5% in ICM and ≥2% in NICM. Mitral regurgitation-fraction×LGE emerged as a significant interaction for the primary end point in ICM (P=0.006), but not in NICM (P=0.971).

CONCLUSIONS

Mitral regurgitation-fraction and LGE are key quantitative cardiac magnetic resonance biomarkers with differential associations with adverse outcomes in ICM and NICM. Optimal prognostic thresholds may provide important clinical risk prognostication and may further facilitate the ability to derive selection criteria to guide therapeutic decision-making.

Transcatheter left ventriculoplasty

Despite significant advances in pharmacological, electrophysiological and valve therapies for heart failure with reduced ejection fraction (HFrEF), the associated morbidity, mortality and healthcare costs remain high. With a constantly growing heart failure population, the existing treatment gap between current and advanced heart failure therapies (e.g., left ventricular [LV] assist devices, heart transplantation) reflects a large unmet need, calling for novel therapeutic approaches. Left ventricular remodelling and dilatation, with or without scar formation, is the hallmark of cardiomyopathy and is associated with poor prognosis. In the era of exciting advances in structural heart interventions, the advent of minimally invasive, device-based therapies directly targeting the LV geometry and promoting physical reverse remodelling has created a new frontier in the battle against heart failure. Interventional heart failure therapy is a rapidly emerging field, encompassing structural heart and minimally invasive hybrid procedures, with two left ventriculoplasty devices currently under investigation in pivotal clinical trials in the US. This review addresses the rationale for left ventriculoplasty, presents the prior surgical and percutaneous attempts in the field, provides an overview of the novel transcatheter left ventriculoplasty devices and their respective trials, and highlights potential challenges associated with establishing such device-based therapies in our armamentarium against heart failure.

Refractory Recurrent Pericarditis After Pericardiectomy in a Young Woman

Pericardiectomy is the recommended treatment for patients with recurrent pericarditis and refractory symptoms despite optimal anti-inflammatory therapy. We present a case of a 40-year-old woman who underwent total pericardiectomy after multiple episodes of pericarditis that was refractory to optimal guideline-derived medical therapy, including anti-inflammatory and biologic agents, who continued to have relapsing symptoms even after pericardiectomy. (Level of Difficulty: Intermediate.)