Trends in the Incidence of In-Hospital Mortality, Cardiogenic Shock, and Utilization of Mechanical Circulatory Support Devices in Myocarditis (Analysis of National Inpatient Sample Data, 2005-2014).

BACKGROUND: Myocarditis may be associated with hemodynamic instability and portends a poor prognosis when associated with cardiogenic shock (CS). There are limited data available on the incidence of in-hospital mortality, CS, and utilization of mechanical circulatory support (MCS) devices in these patients. METHODS: We queried the 2005-2014 National Inpatient Sample databases to identify all patients aged >18 years with myocarditis in the United States. RESULTS: The number of reported cases of myocarditis per 1 million gradually increased from 95 in 2005 to 144 in 2014 (Pfor trend <.01). The trend and incidence of endomyocardial biopsy remained the same despite the increase in clinical diagnosis. Overall, in-hospital mortality was 4.43% of total admissions without a change in overall trend over the study period. We also observed a significant increase in the incidence of CS from 6.94% in 2005 to 11.99% in 2014 (Pfor trend <.01). There was a parallel increase in the utilization of advanced MCS devices during the same time period such as extracorporeal membrane oxygenation or percutaneous cardiopulmonary support (0.32% in 2005 to 2.1% in 2014; P< .01) and percutaneous ventricular assist devices such as Impella/tandem heart (0.176% in 2005 to 1.75% in 2014; P< .01). CONCLUSION: Although the incidence of myocarditis has increased in the last decade, the in-hospital mortality has remained the same despite increases in the incidence of CS, possibly reflecting the benefits of increased usage of advanced MCS devices. We noted that increasing age, presence of multiple comorbidities and CS were associated with an increase in in-patient mortality.

Rupture of Papillary Muscle and Chordae Tendinae Complicating STEMI: A Call for Action.

Papillary muscle rupture (PMR) or chordae tendinae rupture (CTR) is a rare but lethal complication after ST elevation myocardial infarction (STEMI). Due to the rarity of this condition, there are limited studies defining its epidemiology and outcomes. This is a retrospective study from Nationwide Inpatient Sample database from 2002 to 2014 of patients with STEMI and PMR/CTR. Outcomes of interest were incidence of in-hospital mortality, cardiogenic shock (CS), utilization of mechanical circulatory support (MCS) devices and mitral valve procedures (MVPs) among patients with and without rupture. We also performed simulation using the cardiovascular model to better understand the hemodynamics of severe mitral regurgitation and effects of different medications and device therapy. We identified 1,888 patients with STEMI complicated with PMR/CTR. Most of the patients were >65 years of age (65.3%), male (63.6%), and white (82.3%). They had significantly higher incidence of CS, cardiac arrest, and utilization of MCS devices. In-hospital mortality was higher in patients with rupture (41% vs. 7.40%, p < 0.001) which remained unchanged over the study period. Hospitalization cost and length of stay was also higher in them. MVP and revascularization led to better survival rates (27.9% vs. 60.6%, adjusted OR: 0.14; 95% CI: 0.10-0.19; p < 0.001). Despite significant advancement in the revascularization strategy, PMR/CTR after STEMI continues to portend poor prognosis with high inpatient mortality. Cardiogenic shock is a common presentation and is associated with significantly inpatient mortality. Future studies are needed determine the best strategies to improve outcomes in patients with STEMI with PMR/CTR and CS.