Usefulness of Released Cardiac Myosin Binding Protein-C as a Predictor of Cardiovascular Events.

Cardiac myosin binding protein-C (cMyBP-C) is a heart muscle-specific thick filament protein. Elevated level of serum cMyBP-C is an indicator of early myocardial infarction (MI), but its value as a predictor of future cardiovascular disease is unknown. Based on the presence of significant amount of cMyBP-C in the serum of previous study subjects independent of MI, we hypothesized that circulating cMyBP-C is a sensitive indicator of ongoing cardiovascular stress and disease. To test this hypothesis, 75 men and 83 women of similar ages were recruited for a prospective study. They underwent exercise stress echocardiography to provide pre- and poststress blood samples for subsequent determination of serum cMyBP-C levels. The subjects were followed for 1 to 1.5 years. Exercise stress increased serum cMyBP-C in all subjects. Twenty-seven primary events (such as death, MI, revascularization, invasive cardiovascular procedure, or cardiovascular-related hospitalization) and 7 critical events (CE; such as death, MI, stroke, or pulmonary embolism) occurred. After adjusting for sex and cardiovascular risk factors with multivariate Cox regression, a 96% sensitive prestress cMyBP-C threshold carried a hazard ratio of 8.1 with p = 0.041 for primary events. Most subjects (6 of 7) who had CE showed normal ejection fraction on echocardiography. Prestress cMyBP-C demonstrated area under receiver operating curve of 0.91 and multivariate Cox regression hazard ratio of 13.8 (p = 0.000472) for CE. Thus, basal cMyBP-C levels reflected susceptibility for a variety of cardiovascular diseases. Together with its high sensitivity, cMyBP-C holds potential as a screening biomarker for the existence of severe cardiovascular diseases.

Use of Impella 5.0 Prior to Transcatheter Aortic Valve Replacement in a Patient with Severe Aortic Stenosis and Cardiogenic Shock.

The use of transcatheter aortic valve replacement (TAVR) has risen dramatically during the past decade. Notably, the procedure can reduce symptoms and improve prognosis in patients who would otherwise be excluded from intervention due to prohibitive surgical risk. During the same time period, the use of percutaneous mechanical circulatory support devices for patients with severe left ventricular dysfunction, including the Impella System (Abiomed, Inc., Danvers, MA, USA), has also increased. These devices provide superior hemodynamic effects compared to intra-aortic balloon pumping. However, data relating to use of the Impella in patients with both severe left ventricular dysfunction and significant aortic valve disease are limited. Herein is presented the case of a 59-year-old man with severe aortic stenosis and cardiogenic shock who was treated successfully with an Impella 5.0 as a temporizing measure prior to TAVR. A brief review is also provided of the use of mechanical circulatory support devices in this subset of patients. Video 1: Transesophageal echocardiography video demonstrating stenotic aortic valve pre-intervention in side-by-side long and short axes. Video 2: Transthoracic echocardiography video, parasternal short axis, demonstrating Impella 5 in the left ventricle. Video 3: Fluoroscopy video demonstrating deployment of the Edwards SAPIEN transcatheter aortic valve. Video 4: Transesophageal echocardiography video showing the Edwards SAPIEN transcatheter aortic valve in long axis. Video 5: Transesophageal echocardiography video showing the Edwards SAPIEN transcatheter aortic valve in short axis.