First and recurrent events after percutaneous coronary intervention: implications for survival analyses

Objectives. Using composite endpoints and/or only first events in clinical research result in information loss and alternative statistical methods which incorporate recurrent event data exist. We compared information-loss under traditional analyses to alternative models. Design. We conducted a retrospective analysis of patients who underwent percutaneous coronary intervention (Jan2010-Dec2014) and constructed Cox models for a composite endpoint (readmission/death), a shared frailty model for recurrent events, and a joint frailty (JF) model to simultaneously account for recurrent and terminal events and evaluated the impact of heart failure (HF) on the outcome. Results. Among 4901 patients, 2047(41.8%) experienced a readmission or death within 1 year. Of those with recurrent events, 60% had ≥1 readmission and 6% had >4; a total of 121(2.5%) patients died during follow-up. The presence of HF conferred an adjusted Hazard ratio (HR) of 1.32 (95% CI: 1.18-1.47, p < .001) for the risk of composite endpoint (Cox model), 1.44 (95% CI: 1.36-1.52, p < .001) in the frailty model, and 1.34 (95% CI:1.22-1.46, p < .001) in the JF model. However, HF was not associated with death (HR 0.87, 95% CI: 0.52-1.48, p = .61) in the JF model. Conclusions. Using a composite endpoint and/or only the first event yields substantial loss of information, as many individuals endure >1 event. JF models reduce bias by simultaneously providing event-specific HRs for recurrent and terminal events.

Libman-Sacks Endocarditis Involving a Bioprosthesis in the Aortic Valve Position in Systemic Lupus Erythematosus

Described herein is a 39-year-old man with systemic lupus erythematosus not receiving corticosteroid therapy who developed Libman-Sacks endocarditis causing stenosis of a bioprosthesis in the aortic valve position.

Effect of Progressive Left Ventricular Dilatation on Degree of Mitral Regurgitation Secondary to Mitral Valve Prolapse

Described herein is a 71-year-old man who at age 61 was found by echocardiogram to have severe mitral regurgitation (MR) from mitral valve prolapse. During the subsequent 9 years the MR progressively lessened as his left ventricular cavity dilated and his ejection fraction progressively fell such that just before orthotopic heart transplantation the degree of MR was no longer severe, and the prolapse of the mitral leaflets had disappeared. This report describes this unique patient.

Event dependence in the analysis of cardiovascular readmissions postpercutaneous coronary intervention

Recurrent hospitalizations are common in longitudinal studies; however, many forms of cumulative event analyses assume recurrent events are independent. We explore the presence of event dependence when readmissions are spaced apart by at least 30 and 60 days. We set up a comparative framework with the assumption that patients with emergency percutaneous coronary intervention (PCI) will be at higher risk for recurrent cardiovascular readmissions than those with elective procedures. A retrospective study of patients who underwent PCI (January 2008-December 2012) with their follow-up information obtained from a regional database for hospitalization was conducted. Conditional gap time (CG), frailty gamma (FG) and conditional frailty models (CFM) were constructed to evaluate the dependence of events. Relative bias (%RB) in point estimates using CFM as the reference was calculated for comparison of the models. Among 4380 patients, emergent cases were at higher risk as compared with elective cases for recurrent events in different statistical models and time-spaced data sets, but the magnitude of HRs varied across the models (adjusted HR [95% CI]: all readmissions [unstructured data]-CG 1.16 [1.09 to 1.22], FG 1.45 [1.33 to 1.57], CFM 1.24 [1.16 to 1.32]; 30-day spaced-CG1.14 [1.08 to 1.21], FG 1.28 [1.17 to 1.39], CFM 1.17 [1.10 to 1.26]; and 60-day spaced-CG 1.14 [1.07 to 1.22], FG 1.23 [1.13 to 1.34] CFM 1.18 [1.09 to 1.26]). For all of the time-spaced readmissions, we found that the values of %RB were closer to the conditional models, suggesting that event dependence dominated the data despite attempts to create independence by increasing the space in time between admissions. Our analysis showed that independent of the intercurrent event duration, prior events have an influence on future events. Hence, event dependence should be accounted for when analyzing recurrent events and challenges contemporary methods for such analysis.

Validation of the i-STAT handheld activated clotting time for use with bivalirudin

Bivalirudin is being used more frequently as an anticoagulant in the cardiac catheterization laboratory. Newer devices, used to measure activated clotting time (ACT), have not been thoroughly tested for use with bivalirudin. One such device, the i-STAT ACT, measures the generation of activated thrombin to determine the level of anticoagulation. Our study demonstrated a high level of agreement between the i-STAT ACT and the Hemochron ACT in patients anticoagulated with bivalirudin. In addition, the i-STAT was shown to have an extremely high degree of reproducibility.

Percutaneous closure of multiple atrial septal defects with three Amplatzer septal occluder devices

We report on the successful closure of three atrial septal defects with three Amplatzer septal occluders in a 55-year-old woman.