Intra-coronary Imaging for the Evaluation of Plaque Modifications Induced by Drug Therapies for Secondary Prevention.

PURPOSE OF REVIEW: Patients diagnosed with coronary artery disease are at a high risk of subsequent cardiovascular events; therefore, secondary prevention in the form of therapeutic lifestyle changes, and drug therapies is vital. This article aims to review potential application of intra-coronary imaging for the evaluation of plaque modifications, induced by medications for secondary prevention for CAD. RECENT FINDINGS: Intra-coronary imaging provides detailed information on the atherosclerotic plaque which is the primary pathological substrate for the recurrent ischemic cardiovascular events. These modalities can detect features associated with high risk and allow serial in vivo imaging of lesions. Therefore, intravascular imaging tools have been used in landmark studies and played a role in improving our understanding of the disease processes. Changes in size and plaque composition over time can be evaluated by these tools and may help understanding the impact of a treatment. Moreover, surrogate imaging end points can be used when testing new drugs for secondary prevention.

Is heart rate response a reliable marker of adenosine-induced coronary hyperemia?

Introduction Growing evidence supports ischemia-guided management of chest pain, with invasive and non-invasive tests reliant upon achieving adenosine-induced coronary hyperemia (defined as increased blood flow to an organ's perfusion bed). In the non-invasive setting, surrogate markers of hyperemia, such as increases in heart rate, are often used, despite not being formally validated. We tested whether heart rate and other non-invasive indices are reliable markers of coronary hyperemia. Methods The first part involved Doppler flow-based validation of the best pressure-wire markers of hyperemia in 53 patients. Subsequently, using these validated pressure-derived parameters, 265 pressure-wire traces were analysed to determine whether heart rate and other non-invasive parameters correlated with hyperemia. Results In the flow derivation cohort, the best determinant of hyperemia came from having 2 out of 3 of: (1) Ventriculisation of the distal pressure waveform, (2) disappearance of distal dicrotic pressure notch, (3) separation of mean aortic and distal pressures. Within the 244 patients demonstrating hyperemia, non-invasive markers of hyperemia, such as change in heart rate (p = 0.77), blood pressure (p = 0.60) and rate-pressure product (p = 0.86), were poor correlates of coronary hyperemia, with only 37.3% demonstrating a ≥ 10% increase in heart rate that is commonly used to adjudge adenosine-induced hyperemia in the non-invasive setting. Conclusions We demonstrate, by correlation with Doppler-flow data, a validated method of identifying coronary hyperemia within the catheter laboratory using the pressure-wire. We subsequently show that non-invasive parameters, such as heart rate change, are poor predictors of coronary hyperemia during stress imaging protocols that rely upon achieving adenosine-induced hyperemia.

TAVI: New trials and registries offer further welcome evidence - U.S. CoreValve, CHOICE, and GARY.

The introduction of transcatheter aortic valve implantation (TAVI) has resulted in a paradigm shift in the treatment of patients with severe aortic stenosis. Data from the recent U.S CoreValve Trial suggest, for the first time, that TAVI is associated with a significantly higher rate of survival at one year compared to surgical aortic valve replacement (SAVR) in the treatment of high-risk patients affected by severe aortic stenosis. The present review discusses this study and the current evidence about TAVI, for the treatment of severe aortic stenosis, from major trials and real world registries.