New Cardiomechanic Pacing Lead Sensor Based on High Frequency Parameters: Experimental Studies in Sheep

Pacing Lead as a High Frequency Cardiomechanic Sensor . Introduction: The purpose of this study was to investigate the possibility of detecting and quantifying ventricular contraction in sheep utilizing the cardiomechanic sensor based upon the high frequency (HF) parameters measurements on bipolar cardiac pacing leads. Measurement of the HF reflection coefficient yields the lead‐bending signal (LBS) caused by myocardial contraction. The correlation between the lead‐bending acceleration (LBA) expressed as the rate of rise of LBS and LV dP/dt should reveal that LBS may be utilized as a cardiomechanic sensor in implantable cardiac electrotherapy devices. Methods and Results: We implanted 3 different pacing leads and tested the measurement system in 9 sheep (42 ± 6 kg) at baseline and during acute hemodynamic intervention with dobutamine infusion and tachycardia induced by VVI pacing at 200 bpm. A stable, consistent, and reproducible LBS was obtained in all sheep during the implantation procedure and 4 months after the implantation during different experimental conditions that included hemodynamic interventions. The dependence between LBA_max and LV dP/dt_max was found to be statistically significant and with high Pearson's correlation coefficient (r = 0.855, P <0.001). We could also observe the hemodynamic deterioration caused by fast ventricular pacing with the decrease of LV dp/dt and LBA compared with sinus rhythm. Conclusion: This study confirms the feasibility and efficacy of the hemodynamic sensor based upon HF lead parameters. Moreover, it was demonstrated that LBA_max is highly correlated to the ventricular contractility and, therefore, can be efficiently used as a hemodynamic and cardiomechanic sensor. (J Cardiovasc Electrophysiol, Vol. 24, pp. 338‐346, March 2013)     

Development and Validation of a Risk Scoring Model to Predict Net Adverse Cardiovascular Outcomes after Primary Percutaneous Coronary Intervention in Patients Pretreated with 600 mg Clopidogrel: Rationale and Design of the RISK-PCI Study

Background: No comprehensive primary PCI (pPCI) risk model to predict net adverse cardiovascular events (NACE) has been reported with the use of clopidogrel 600 mg, which is now considered the standard loading dose. The primary hypothesis of the RISK-PCI trial is that an accurate risk prediction may be achieved by using clinical, angiographic, and procedural variables available at the time of intervention.
Methods: The present single-center, longitudinal, cohort study will include 1,750 consecutive patients with ST-elevation myocardial infarction (STEMI), undergoing pPCI after pretreatment with 300 mg aspirin and 600 mg clopidogrel. The primary end-points of the trial (NACE) include major adverse cardiovascular events (MACE) and major bleeding. A logistic regression model will be developed to predict 30-day and 1-year NACE after pPCI. A risk score derived from study set data will be validated using validation set data.
Results: Until June 1, 2008, 1,166 patients have been enrolled. Thirty-day follow-up is available in 1,007 patients.
Conclusions: The RISK-PCI study is designed to develop an accurate risk scoring system, using variables available at the time of intervention, to predict long-term adverse outcomes after pPCI.
Trial Registration: Current Controlled Trials Register—ISRCTN83474650— http://www.controlled-trials.com/ISRCTN83474650) .