Jacob C. Townsend

Usefulness of International Normalized Ratio to Predict Bleeding Complications in Patients With End-Stage Liver Disease Who Undergo Cardiac Catheterization

Patients with end-stage liver disease frequently require invasive cardiac procedures in preparation for liver transplantation. Because of the impaired hepatic function, these patients often have a prolonged prothrombin time and elevated international normalized ratio (INR). To determine whether an abnormal prothrombin time/INR is predictive of bleeding complications from invasive cardiac procedures, we retrospectively reviewed, for bleeding complications, the databases and case records of our series of patients with advanced cirrhosis who underwent cardiac catheterization. A total of 157 patients underwent isolated right-sided heart catheterization, and 83 underwent left-sided heart catheterization or combined left- and right-sided heart catheterization. The INR ranged from 0.93 to 2.35. No major procedure-related complications occurred. Several patients in each group required a blood transfusion for gastrointestinal bleeding but not for procedure-related bleeding. No significant change was found in the hemoglobin after right-sided or left-sided heart catheterization, and no correlation was found between the preprocedure INR and the change in postprocedure hemoglobin. When comparing patients with a normal (≤1.5) and elevated (>1.5) INR, no significant difference in hemoglobin after the procedure was found in either group. In conclusion, despite an elevated INR, patients with end-stage liver disease can safely undergo invasive cardiac procedures. An elevated INR does not predict catheterization-related bleeding complications in this patient population.

Coronary CT Angiography versus Conventional Cardiac Angiography for Therapeutic Decision Making in Patients with High Likelihood of Coronary Artery Disease

PURPOSE To assess the efficacy of coronary computed tomographic (CT) angiography for therapeutic decision making in patients with high likelihood of coronary artery disease (CAD)-specifically the ability of coronary CT angiography to help differentiate patients without and patients with a need for revascularization and determine the appropriate revascularization procedure. MATERIALS AND METHODS The study protocol was approved by institutional review board, with written informed consent from all patients. The study was conducted in compliance with HIPAA. One hundred eighty-five consecutive symptomatic patients (121 men; mean age, 59.4 years±9.7) with a positive single photon emission computed tomography (SPECT) myocardial perfusion study underwent coronary CT angiography and conventional cardiac angiography (hereafter, cardiac catheterization). The management strategy (conservative treatment vs revascularization) and revascularization procedure (percutaneous coronary intervention [PCI] vs coronary artery bypass graft surgery [CABG]) were prospectively selected on the basis of a combination of coronary CT angiography and SPECT. In addition, the authors calculated the accuracy, sensitivity, specificity, and negative and positive predictive values of coronary CT angiography in the detection of obstructive CAD and the selection of a revascularization strategy. Cardiac catheterization was used as the standard of reference. RESULTS Of the 185 patients, 113 (61%) did not undergo revascularization and 42 (23%) were free of CAD. In 178 patients (96%), the same therapeutic strategy (conservative treatment vs revascularization) was chosen on the basis of coronary CT angiography and catheterization. All patients in need of revascularization were identified with coronary CT angiography. When revascularization was indicated, the same procedure (PCI vs CABG) was chosen in 66 of 72 patients (92%). CONCLUSION In patients with high likelihood of CAD, the performance of coronary CT angiography in the differentiation of patients without and patients with a need for revascularization and the selection of a revascularization strategy was similar to that of cardiac catheterization; accordingly, coronary CT angiography has the potential to limit the number of patients without obstructive CAD who undergo cardiac catheterization and to inform decision making regarding revascularization.

Left ventricular end-diastolic pressure affects measurement of fractional flow reserve

BACKGROUND Fractional flow reserve (FFR), the hyperemic ratio of distal (Pd) to proximal (Pa) coronary pressure, is used to identify the need for coronary revascularization. Changes in left ventricular end-diastolic pressure (LVEDP) might affect measurements of FFR. METHODS AND MATERIALS LVEDP was recorded simultaneously with Pd and Pa during conventional FFR measurement as well as during additional infusion of nitroprusside. The relationship between LVEDP, Pa, and FFR was assessed using linear mixed models. RESULTS Prospectively collected data for 528 cardiac cycles from 20 coronary arteries in 17 patients were analyzed. Baseline median Pa, Pd, FFR, and LVEDP were 73 mmHg, 49 mmHg, 0.69, and 18 mmHg, respectively. FFR<0.80 was present in 14 arteries (70%). With nitroprusside median Pa, Pd, FFR, and LVEDP were 61 mmHg, 42 mmHg, 0.68, and 12 mmHg, respectively. In a multivariable model for the entire population LVEDP was positively associated with FFR such that FFR increased by 0.008 for every 1-mmHg increase in LVEDP (beta=0.008; P<0.001), an association that was greater in obstructed arteries with FFR<0.80 (beta=0.01; P<0.001). Pa did not directly affect FFR in the multivariable model, but an interaction between LVEDP and Pa determined that LVEDPs effect on FFR is greater at lower Pa. CONCLUSIONS LVEDP was positively associated with FFR. The association was greater in obstructive disease (FFR<0.80) and at lower Pa. These findings have implications for the use of FFR to guide revascularization in patients with heart failure. SUMMARY FOR ANNOTATED TABLE OF CONTENTS The impact of left ventricular diastolic pressure on measurement of fractional flow reserve (FFR) is not well described. We present a hemodynamic study of the issue, concluding that increasing left ventricular diastolic pressure can increase measurements of FFR, particularly in patients with FFR<0.80 and lower blood pressure.

Everolimus-eluting stents in interventional cardiology

Bare metal stents have a proven safety record, but limited long-term efficacy due to in-stent restenosis. First-generation drug-eluting stents successfully countered the restenosis rate, but were hampered by concerns about their long-term safety. Second generation drug-eluting stents have combined the low restenosis rate of the first generation with improved long-term safety. We review the evolution of drug-eluting stents with a focus on the safety, efficacy, and unique characteristics of everolimus-eluting stents.

Alcohol septal ablation for obstructive hypertrophic cardiomyopathy: Outcomes in young, middle-aged, and elderly patients

We compared the efficacy and safety of alcohol septal ablation (ASA) for obstructive hypertrophic cardiomyopathy (HCM) in young, middle‐aged, and elderly patients.

Comparison of percutaneous coronary intervention safety before and during the establishment of a transradial program at a teaching hospital.

This study sought to examine the safety of percutaneous coronary intervention (PCI) before and during de novo establishment of a transradial (TR) program at a teaching hospital. TR access remains underused in the United States, where cardiology fellowship programs continue to produce cardiologists with little TR experience. Establishment of TR programs at teaching hospitals may affect PCI safety. Starting in July 2009 a TR program was established at a teaching hospital. PCI-related data for academic years 2008 to 2009 (Y1) and 2009 to 2010 (Y2) were prospectively collected and retrospectively analyzed. Of 1,366 PCIs performed over 2 years, 0.1% in Y1 and 28.7% in Y2 were performed by TR access. No major complications were identified in 194 consecutive patients undergoing TR PCI, and combined bleeding and vascular complication rates were lower in Y2 versus Y1 (0.7% vs 2.0%, p = 0.05). Patients treated in Y2 versus Y1 and by TR versus transfemoral approach required slightly more fluoroscopy but similar contrast volumes and had similar procedural durations, lengths of stay, and predischarge mortality rates. PCI success rates were 97% in Y1, 97% in Y2, and 98% in TR cases. TR PCIs were performed by 13 cardiology fellows and 9 attending physicians, none of whom routinely performed TR PCI previously. In conclusion, de novo establishment of a TR program improved PCI safety at a teaching hospital. TR programs are likely to improve PCI safety at other teaching hospitals and should be established in all cardiology fellowship training programs.

Comparison of Lipid Deposition at Coronary Bifurcations Versus at Nonbifurcation Portions of Coronary Arteries as Determined by Near-Infrared Spectroscopy

Atherosclerosis has been shown to develop preferentially at sites of coronary bifurcation, yet culprit lesions resulting in ST-elevation myocardial infarction do not occur more frequently at these sites. We hypothesized that these findings can be explained by similarities in intracoronary lipid and that lipid and lipid core plaque would be found with similar frequency in coronary bifurcation and nonbifurcation segments. One hundred seventy bifurcations were identified, 156 of which had comparative nonbifurcation segments proximal and/or distal to the bifurcation. We compared lipid deposition at bifurcation and nonbifurcation segments in coronary arteries using near-infrared spectroscopy (NIRS), a novel method for the in vivo detection of coronary lipid. Any NIRS signal for the presence of lipid was found with similar frequency in bifurcation and nonbifurcation segments (79% vs 74%, p = NS). Lipid core burden index, a measure of total lipid quantity indexed to segment length, was similar across bifurcation segments as well as their proximal and distal controls (lipid core burden index 66.3 ± 106, 67.1 ± 116, and 66.6 ± 104, p = NS). Lipid core plaque, identified as a high-intensity focal NIRS signal, was found in 21% of bifurcation segments, and 20% of distal nonbifurcation segments (p = NS). In conclusion, coronary bifurcations do not appear to have higher levels of intracoronary lipid or lipid core plaque than their comparative nonbifurcation regions.

Diagnostic yield and accuracy of coronary CT angiography after abnormal nuclear myocardial perfusion imaging

We aimed to determine the diagnostic yield and accuracy of coronary CT angiography (CCTA) in patients referred for invasive coronary angiography (ICA) based on clinical concern for coronary artery disease (CAD) and an abnormal nuclear stress myocardial perfusion imaging (MPI) study. We enrolled 100 patients (84 male, mean age 59.6 ± 8.9 years) with an abnormal MPI study and subsequent referral for ICA. Each patient underwent CCTA prior to ICA. We analyzed the prevalence of potentially obstructive CAD (≥50% stenosis) on CCTA and calculated the diagnostic accuracy of ≥50% stenosis on CCTA for the detection of clinically significant CAD on ICA (defined as any ≥70% stenosis or ≥50% left main stenosis). On CCTA, 54 patients had at least one ≥50% stenosis. With ICA, 45 patients demonstrated clinically significant CAD. A positive CCTA had 100% sensitivity and 84% specificity with a 100% negative predictive value and 83% positive predictive value for clinically significant CAD on a per patient basis in MPI positive symptomatic patients. In conclusion, almost half (48%) of patients with suspected CAD and an abnormal MPI study demonstrate no obstructive CAD on CCTA.