Trial Design Principles for Patients at High Bleeding Risk Undergoing PCI: JACC Scientific Expert Panel.

Investigating the balance of risk for thrombotic and bleeding events after percutaneous coronary intervention (PCI) is especially relevant for patients at high bleeding risk (HBR). The Academic Research Consortium for HBR recently proposed a consensus definition in an effort to standardize the patient population included in HBR trials. The aim of this consensus-based document, the second initiative from the Academic Research Consortium for HBR, is to propose recommendations to guide the design of clinical trials of devices and drugs in HBR patients undergoing PCI. The authors discuss the designs of trials in HBR patients undergoing PCI and various aspects of trial design specific to HBR patients, including target populations, intervention and control groups, primary and secondary outcomes, and timing of endpoint reporting.

Comparison of electrocardiogram and intrathoracic electrogram signals for detection of ischemic ST segment changes during normal sinus and ventricular paced rhythms.

INTRODUCTION: The aim of this study was to compare surface ECGs with electrograms (EGM) that are available from implanted devices for the ability to detect ischemic ST segment changes during normal sinus (NS) and ventricular paced (VP) rhythms. METHODS AND RESULTS: ECG leads I, II, and V2, right atrial ring to left pectoral patch (representing the can of the device), right ventricular ring to left pectoral patch, and right atrial ring to right ventricular ring EGM were recorded continuously during percutaneous transluminal coronary angioplasty. One balloon inflation (> or = 60 sec) was analyzed from each of 22 NS and 22 VP subjects. The parameter AST was defined as the maximum absolute ST segment deviation (from isoelectric) during the first 60 seconds of inflation, measured relative to the baseline (preinflation) ST segment deviation. For EGM, a normalized deltaST was defined as the AST divided by the ratio of QRS amplitudes of EGM to ECG. During NS, the deltaST for EGM (0.43 mV) was significantly larger than that of ECG (0.09 mV, P = 0.0001) but the normalized deltaST for EGM (0.11 mV) was comparable to that of ECG (0.09 mV, P = 0.45). During VP, the AST for EGM (1.08 mV) was significantly larger than that of ECG (0.17 mV, P = 0.0001), but the normalized AST for EGM (0.11 mV) was significantly smaller than that of ECG (0.17 mV, P = 0.02). CONCLUSION: During both NS and VP, ischemic ST segment changes were significantly larger in EGM than in ECG. Much of this difference appears to be related to larger amplitudes of EGM signals. (J