Laser Atherectomy for Treatment of Femoropopliteal In-Stent Restenosis.

PURPOSE: To investigate if laser atherectomy with adjunctive balloon angioplasty can improve endovascular treatment outcomes for femoropopliteal in-stent restenosis (ISR). METHODS: A dual center study included 135 symptomatic patients (mean age 71 years; 76 men) who underwent endovascular treatment of femoropopliteal ISR between 2006 and 2013. Of these, 54 (40%) were treated with laser atherectomy and the remaining 81 patients with balloon angioplasty alone. Angiographic images were reviewed for lesion morphology and characteristics, TransAtlantic InterSociety Consensus (TASC) II classification, and distal runoff. Class I ISR was defined as focal lesions ≤50 mm, class II ISR as lesions >50 mm, and class III ISR as stent total occlusion. Recurrent ISR was determined by a peak systolic velocity ratio >2.4 by duplex ultrasound. RESULTS: Patients treated with laser atherectomy had longer mean ISR lesion length (222 vs 114 mm, p<0.001) and more class III ISR (69% vs 20%, p=0.001). There was no association between laser atherectomy and rates of recurrent restenosis or occlusion for patients with class I/II ISR, but there was a significantly lower rate of target lesion revascularization at 2 years among patients treated with laser atherectomy (14% vs 44%, p=0.05). In comparison, patients with class III ISR treated with laser atherectomy had lower rates of recurrent restenosis at 1 year (54% vs 91%, p=0.05) and 2 years (69% vs 100%, p=0.05). Patients with class III ISR treated with laser atherectomy also had lower rates of recurrent in-stent occlusion at 2-year follow-up (33% vs 71%, p=0.04). CONCLUSION: When used to treat complex ISR, including in-stent occlusions, laser atherectomy with adjunctive balloon angioplasty may be associated with improved patency.

Current practice for determining pulmonary capillary wedge pressure predisposes to serious errors in the classification of patients with pulmonary hypertension.

BACKGROUND: Accurate measurement of left ventricular filling pressure is important to distinguish between category 1 pulmonary arterial hypertension (PAH) and category 2 pulmonary hypertension (PH) from left heart diseases (PH-HFpEF). We hypothesized that the common practice of relying on the digitized mean pulmonary capillary wedge pressure (PCWP-digital) results in erroneous recordings, whereas end-expiratory PCWP measurements (PCWP-end Exp) provide a reliable surrogate measurement for end-expiratory left ventricular end-diastolic pressure (LVEDP-end Exp-end Exp). METHODS: We prospectively performed left and right cardiac catheterization on 61 patients referred for evaluation of PH and compared the LVEDP-end Exp to end-expiration to the (a) PCWP-end Exp and (b) PCWP-digital. RESULTS: The PCWP-end Exp was a more reliable reflection of LVEDP-end Exp (mean 13.2 mm Hg vs 12.4 mm Hg; P, nonsignificant) than PCWP-digital (mean 8.0 mm Hg vs 12.4 mm Hg, P < .05). Bland-Altman analysis of PCWP-digital and LVEDP-end Exp revealed a mean bias of -4.4 mm Hg with 95% limits of agreement of -11.3 to 2.5 mm Hg. Bland-Altman analysis of PCWP-end Exp and LVEDP-end Exp revealed a mean bias of 0.9 mm Hg with 95% limits of agreement of -5.2 to 6.9 mm Hg. If PCWP-digital were used to define LVEDP-end Exp, 14 (27%) of 52 patients would have been misclassified as having PAH rather than PH-HFpEF. Patients with obesity and hypoxia were particularly more likely to be misclassified as PAH instead of PH-HFpEF if PCWP-digital was used to define LVEDP-end Exp (odds ratio 8.1, 95% CI 1.644-40.04, P = .01). CONCLUSIONS: The common practice of using PCWP-digital instead of PCWP-end Exp results in a significant underestimation of LVEDP-end Exp. In our study, this translated to nearly 30% of patients being misclassified as having PAH rather than PH from HFpEF.

Stress-only imaging in patients with prior SPECT MPI: a simulation study.

OBJECTIVES: The aim of this study was to determine if omitting the repeat resting scan in patients who had prior single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) would have an impact on the interpretation of the stress test. BACKGROUND: Current guidelines recommend stress and rest imaging for SPECT MPI studies. Stress-only imaging has also entered the guidelines as a feasible option in low-risk patients but has not been studied in high-risk patients. METHODS: Two independent readers interpreted 47 consecutive MPIs with prior images to determine if the repeat resting scan had an impact on interpretation of the stress test images. In this retrospective analysis, we compared interpretation of stress-only SPECT images using the old rest image for comparison versus conventional rest-stress SPECT imaging. Both readers were blinded to study results. The primary end point of this study was a comparison of summed difference scores (SDS) from stress-only interpretation compared to standard rest-stress interpretation. RESULTS: In this study, 36% (98/272) of patients had previous SPECT MPI. Of these patients, 48% (n = 47) were eligible for stress-only imaging. There was strong agreement between the SDS from the new stress versus old rest image compared with the new stress versus new rest image (r = 0.866, P < .001) with a mean difference in SDS of 0.6 ± 1.7. In this population, 41 of the 47 studies (87%) could have been performed with a stress-only SPECT MPI with comparison with the prior resting study. Starting with the stress-only protocol would have reduced the radiation in this population by 76%. CONCLUSIONS: Very similar data is obtained with stress-only imaging in patients who have a prior resting study. Our study suggests that the stress-only imaging may possibly be expanded to populations who have been studied previously or are at higher risk, reserving the option to add a resting study if the interpretation of the stress-only study is unclear.

Facility-level association of preoperative stress testing and postoperative adverse cardiac events.

BACKGROUND: Despite limited indications, preoperative stress testing is often used prior to non-cardiac surgery. Patient-level analyses of stress testing and outcomes are limited by case mix and selection bias. Therefore, we sought to describe facility-level rates of preoperative stress testing for non-cardiac surgery, and to determine the association between facility-level preoperative stress testing and postoperative major adverse cardiac events (MACE). METHODS: We identified patients undergoing non-cardiac surgery within 2 years of percutaneous coronary intervention in the Veterans Affairs (VA) Health Care System, from 2004 to 2011, facility-level rates of preoperative stress testing and postoperative MACE (death, myocardial infarction (MI) or revascularisation within 30 days). We determined risk-standardised facility-level rates of stress testing and postoperative MACE, and the relationship between facility-level preoperative stress testing and postoperative MACE. RESULTS: Among 29 937 patients undergoing non-cardiac surgery at 131 VA facilities, the median facility rate of preoperative stress testing was 13.2% (IQR 9.7%-15.9%; range 6.0%-21.5%), and 30-day postoperative MACE was 4.0% (IQR 2.4%-5.4%). After risk standardisation, the median facility-level rate of stress testing was 12.7% (IQR 8.4%-17.4%) and postoperative MACE was 3.8% (IQR 2.3%-5.6%). There was no correlation between risk-standardised stress testing and composite MACE at the facility level (r=0.022, p=0.81), or with individual outcomes of death, MI or revascularisation. CONCLUSIONS: In a national cohort of veterans undergoing non-cardiac surgery, we observed substantial variation in facility-level rates of preoperative stress testing. Facilities with higher rates of preoperative stress testing were not associated with better postoperative outcomes. These findings suggest an opportunity to reduce variation in preoperative stress testing without sacrificing patient outcomes.

Peripheral artery disease in patients with diabetes: Epidemiology, mechanisms, and outcomes.

Peripheral artery disease (PAD) is the atherosclerosis of lower extremity arteries and is also associated with atherothrombosis of other vascular beds, including the cardiovascular and cerebrovascular systems. The presence of diabetes mellitus greatly increases the risk of PAD, as well as accelerates its course, making these patients more susceptible to ischemic events and impaired functional status compared to patients without diabetes. To minimize these cardiovascular risks it is critical to understand the pathophysiology of atherosclerosis in diabetic patients. This, in turn, can offer insights into the therapeutic avenues available for these patients. This article provides an overview of the epidemiology of PAD in diabetic patients, followed by an analysis of the mechanisms by which altered metabolism in diabetes promotes atherosclerosis and plaque instability. Outcomes of PAD in diabetic patients are also discussed, with a focus on diabetic ulcers and critical limb ischemia.

Mechanistic insights and characterization of sickle cell disease-associated cardiomyopathy.

BACKGROUND: Cardiovascular disease is an important cause of morbidity and mortality in sickle cell disease (SCD). We sought to characterize sickle cell cardiomyopathy using multimodality noninvasive cardiovascular testing and identify potential causative mechanisms. METHODS AND RESULTS: Stable adults with SCD (n=38) and healthy controls (n=13) prospectively underwent same day multiparametric cardiovascular magnetic resonance (cine, T2* iron, vasodilator first pass myocardial perfusion, and late gadolinium enhancement imaging), transthoracic echocardiography, and applanation tonometry. Compared with controls, patients with SCD had severe dilation of the left ventricle (124±27 vs 79±12 mL/m(2)), right ventricle (127±28 vs 83±14 mL/m(2)), left atrium (65±16 vs 41±9 mL/m(2)), and right atrium (78±17 vs 56±17 mL/m(2); P<0.01 for all). Patients with SCD also had a 21% lower myocardial perfusion reserve index than control subjects (1.47±0.34 vs 1.87±0.37; P=0.034). A significant subset of patients with SCD (25%) had evidence of late gadolinium enhancement, whereas only 1 patient had evidence of myocardial iron overload. Diastolic dysfunction was present in 26% of patients with SCD compared with 8% in controls. Estimated filling pressures (E/e', 9.3±2.7 vs 7.3±2.0; P=0.0288) were higher in patients with SCD. Left ventricular dilation and the presence of late gadolinium enhancement were inversely correlated to hepatic T2* times (ie, hepatic iron overload because of frequent blood transfusions; P<0.05 for both), whereas diastolic dysfunction and increased filling pressures were correlated to aortic stiffness (augmentation pressure and index, P<0.05 for all). CONCLUSIONS: Sickle cell cardiomyopathy is characterized by 4-chamber dilation and in some patients myocardial fibrosis, abnormal perfusion reserve, diastolic dysfunction, and only rarely myocardial iron overload. Left ventricular dilation and myocardial fibrosis are associated with increased blood transfusion requirements, whereas left ventricular diastolic dysfunction is predominantly correlated with increased aortic stiffness. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01044901.