Matthew D. Saybolt

Naloxone in cardiac arrest with suspected opioid overdoses

INTRODUCTION Naloxones use in cardiac arrest has been of recent interest, stimulated by conflicting results in both human case reports and animal studies demonstrating antiarrhythmic and positive ionotropic effects. We hypothesized that naloxone administration during cardiac arrest, in suspected opioid overdosed patients, is associated with a change in cardiac rhythm. METHODS From a database of 32,544 advanced life support (ALS) emergency medical dispatches between January 2003 and December 2007, a retrospective chart review was completed of patients receiving naloxone in cardiac arrest. Forty-two patients in non-traumatic cardiac arrest were identified. Each patient received naloxone because of suspicion by a paramedic of acute opioid use. RESULTS Fifteen of the 36 (42%) (95% confidence interval [CI]: 26-58) patients in cardiac arrest who received naloxone in the pre-hospital setting had an improvement in electrocardiogram (EKG) rhythm. Of the participants who responded to naloxone, 47% (95% CI: 21-72) (19% [95% CI: 7-32] of all study subjects) demonstrated EKG rhythm changes immediately following the administration of naloxone. DISCUSSION Although we cannot support the routine use of naloxone during cardiac arrest, we recommend its administration with any suspicion of opioid use. Due to low rates of return of spontaneous circulation and survival during cardiac arrest, any potential intervention leading to rhythm improvement is a reasonable treatment modality.

Low-Flow Severe Aortic Stenosis: Evolving Role of Transcatheter Aortic Valve Replacement

The definition of severe aortic stenosis has classically and retrospectively been based on the natural history of patients with medically managed aortic stenosis and preserved left ventricular function in an era where surgical aortic valve replacement was the sole therapy. We now recognize that this disease is more heterogeneous and includes important subsets of patients with low stroke volume index (low flow) and low-gradient with reduced (classical) or preserved (paradoxical) ejection fraction. These patients pose diagnostic and treatment dilemmas, requiring a comprehensive assessment with integration of multimodality imaging, testing, and clinical assessment. Surgery in these patients has been associated with higher operative mortality and lower long-term survival. Transcatheter aortic valve replacement (TAVR), because of its less-invasive nature, avoidance of the detrimental effects of cardiopulmonary bypass, and larger effective orifice area, offers several potential advantages. Studies of TAVR in low-flow severe aortic stenosis patients have demonstrated that TAVR has a significant mortality benefit compared with medical therapy and a similar benefit compared with surgery. Both low flow and low ejection fraction have emerged as important factors in predicting mortality post-TAVR, with particularly poor survival when flow or ejection fraction fail to improve. The recognition, diagnosis, and treatment of patients with low-flow severe aortic stenosis remains challenging. It is likely that TAVR will play an increasingly important role in the management of these patients.

Educating the MACRA-Ready Cardiologist: Developing Competencies in Value-Based Cardiovascular Medicine

“If you always do what you’ve always done, you always get what you’ve always gotten.”—Jessie Potter [(1)][1] The Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) is considered to be one of the largest changes to Medicare physician reimbursement since its launch in 1965.

Coronary Stent Fracture: A New Form of Patient-Prosthesis Mismatch?

Perfection is not attainable, but if we chase perfection we can catch excellence.—Vince Lombardi [(1)][1] Improvements in technology and technique have been associated with continuous, steady declines in post-percutaneous coronary intervention (PCI) adverse events, including clinically

Ability of combined Near-Infrared Spectroscopy-Intravascular Ultrasound (NIRS-IVUS) imaging to detect lipid core plaques and estimate cap thickness in human autopsy coronary arteries

The ability to determine plaque cap thickness during catheterization is thought to be of clinical importance for plaque vulnerability assessment. While methods to compositionally assess cap integrity are in development, a method utilizing currently available tools to measure cap thickness is highly desirable. NIRS-IVUS is a commercially available dual imaging method in current clinical use that may provide cap thickness information to the skilled reader; however, this is as yet unproven. Ten autopsy hearts (n=15 arterial segments) were scanned with the multimodality NIRS-IVUS catheter (TVC Imaging System, Infraredx, Inc.) to identify lipid core plaques (LCPs). Skilled readers made predictions of cap thickness over regions of chemogram LCP, using NIRS-IVUS. Artery segments were perfusion fixed and cut into 2 mm serial blocks. Thin sections stained with Movat’s pentachrome were analyzed for cap thickness at LCP regions. Block level predictions were compared to histology, as classified by a blinded pathologist. Within 15 arterial segments, 117 chemogram blocks were found by NIRS to contain LCP. Utilizing NIRSIVUS, chemogram blocks were divided into 4 categories: thin capped fibroatheromas (TCFA), thick capped fibroatheromas (ThCFA), pathological intimal thickening (PIT)/lipid pool (no defined cap), and calcified/unable to determine cap thickness. Sensitivities/specificities for thin cap fibroatheromas, thick cap fibroatheromas, and PIT/lipid pools were 0.54/0.99, 0.68/0.88, and 0.80/0.97, respectively. The overall accuracy rate was 70.1% (including 22 blocks unable to predict, p = 0.075). In the absence of calcium, NIRS-IVUS imaging provided predictions of cap thickness over LCP with moderate accuracy. The ability of this multimodality imaging method to identify vulnerable coronary plaques requires further assessment in both larger autopsy studies, and clinical studies in patients undergoing NIRS-IVUS imaging.

Evaluation of combined near-IR spectroscopic (NIRS)-IVUS imaging as a means to detect lipid-rich plaque burden in human coronary autopsy specimens

Intracoronary near-infrared spectroscopy (NIRS) can identify lipid in the coronary arteries, but lacks depth resolution. A novel catheter is currently in clinical use that combines NIRS with intravascular ultrasound (IVUS), which provides depth-resolved structural information via the IVUS modality. A measure designated as lipid-rich plaque burden (LRPB) has been proposed as a means to interpret the combined acoustic and optical information of NIRS-IVUS. LRPB is defined as the area created by the intersection of the NIRS lipid-rich arc with the corresponding IVUS-measured plaque burden. We determined the correlation in human coronary autopsy specimens between LRPB, a measure of lipid presence and extent available via intravascular imaging in patients, and the area of lipid-rich plaque as determined by the gold-standard of histology. Fifteen artery segments from 8 human autopsy hearts were imaged with the NIRS-IVUS system (TVC Imaging System, Infraredx Inc., Burlington, MA). Arteries were imaged in a specialty fixture that assured accurate co-registration between imaging and histology. The arteries were then fixed and divided into 2 mm blocks for histological staining. Pathological contouring of lipid-rich areas was performed on the stained thin sections for 54 lipid-rich blocks. Computation of LRPB was performed on transverse NIRS-IVUS frames corresponding to the histologic sections. The quantified LRPB was frequently higher than the lipid-rich plaque area determined by histology, because the region denoted by the EEL and lumen within the NIRS lipid-rich arc is not entirely comprised of lipid. Overall, a moderate to strong correlation (R = 0.73) was found between LRPB determined by NIRS-IVUS imaging and the lipid-rich plaque area determined by histology. LRPB, which can be measured in patients with NIRS-IVUS imaging, corresponds to the amount of lipid-rich plaque in a coronary artery. LRPB should be evaluated in prospective clinical trials for its ability to identify vulnerable plaques.

TCT-603 Traditional Coronary Risk Factors are Only Weakly Associated with Collagen Integrity of Caps over Lipid Cores in Selected Coronary Autopsy Specimens

TCT-603 Traditional Coronary Risk Factors are Only Weakly Associated with Collagen Integrity of Caps over Lipid Cores in Selected Coronary Autopsy Specimens Stephanie Grainger, Cherry Greiner, Jimmy Su, matthew saybolt, William Pickering, Robert Wilensky, Joel Raichlen, James Muller, Sean Madden Infraredx, Inc., Burlington, Massachusetts, United States; Infraredx, Burlington, Massachusetts, United States; Infraredx, Burlington, Massachusetts, United States; Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, United States; Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States; Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, United States; Northwestern University Feinberg School of Medicine; InfraReDx, Inc., Burlington, Massachusetts, United States; Unknown, Burlington, Massachusetts, United States

TCT-575 Combined near-infrared spectroscopy and intravascular ultrasound (NIRS-IVUS) coronary imaging as a means to improve prediction of events by IVUS plaque burden alone

Previous clinical studies have shown that plaque burden (PB) >70%, as measured by intravascular ultrasound (IVUS), is predictive of future coronary events. But because IVUS tracing of PB is time-consuming, results from PROSPECT I did not significantly alter clinical practice. In addition to PB, the

Going Green for Vulnerable Plaque Detection

Vulnerable plaques make vulnerable patients vulnerable. However, finding the vulnerable plaque that will cause future cardiac instability has proven difficult. Despite a number of invasive intravascular diagnostic modalities, our capacity to accurately identify unstable lesions or even those