16 research outputs found
Role and Rationale for Hybrid Coronary Artery Revascularization
The optimal revascularization strategy for patients with multi-vessel coronary artery disease remains controversial. The advent of percutaneous coronary intervention (PCI) has challenged the superiority of coronary artery bypass graft (CABG) surgery for multi-vessel disease. In the late 1990s, an integrated approach, now referred to as “hybrid coronary revascularization” (HCR), was pioneered combining CABG and PCI to offer appropriate patients a less invasive option for revascularization while still capitalizing on the superior patency rates of the left internal mammary artery (LIMA) to the left anterior descending (LAD) artery bypass . The operative techniques continue to evolve as well as the timing strategies for intervention and use of anti-platelet therapy. While more research is needed, current data supports hybrid coronary revascularization as a promising technique to optimize outcomes in patients with multi-vessel coronary artery disease
Two cases of monoclonal nodular pulmonary amyloidosis and review of the literature
Nodular pulmonary amyloidosis (NPA) is an uncommon pathology of insoluble protein depositing in pulmonary parenchyma. This localized pulmonary form of amyloidosis is most often found to contain combinations of kappa and lambda immunoglobulin light chain and immunoglobulin heavy chain proteins with a polyclonal lymphoplasmacystic infiltrate. Herein we present two cases of NPA of the rarely reported monoclonal (light-chain restricted) form with review of the literature and discussion of the clinical, radiographic, and histologic features of NPA
Long-term survival after CABG in diabetics with aggressive risk factor management
Objectives: Diabetes is a well-established risk factor for cardiovascular disease, and diabetics have a threefold increase in risk of death from cardiovascular disease compared to non-diabetics. Following coronary artery bypass grafting, tight glycemic control improves short-term outcomes, however limited data exist for long-term outcomes. Here we examine these outcomes in diabetics using aggressive risk factor management.
Methods: A retrospective review of all patients under-going coronary artery bypass between 1991 and 2000 at a single Veterans Affairs Medical Center was undertaken. 973 patients were included, 313 with diabetes and 660 without. Strict glucose control was maintained for all patients. Additional risk factor modification, including anti-platelets medications, statins, and beta blockers were also used. Survival analysis was performed.
Results: The diabetic group was at higher risk, with age, BSA, and NYHA class all being greater (p \u3c 0.05). The mean follow-up time was 6.7 ± 3 years. There were 28 deaths/1000 person-years for non-diabetics, and 48 deaths/1000 person-years for diabetics. Survival rates were significantly higher for non-diabetics (72% versus 58% in the diabetic group, p \u3c 0.001). Cox proportional hazard analysis demonstrated mortality risk was 57% higher for diabetic patients (hazard ratio = 1.57; CI: 1.19 - 2.09; p = 0.002). The mortality risk in diabetics with and without prior MI was similar (HR = 0.83; CI: 0.54 - 1.28; p = 0.40).
Conclusions: Diabetics undergoing coronary bypass have poorer long-term survival than non-diabetics despite perioperative glycemic control and risk factor modification. The long-term survival decrease in diabetics with history of MI is attenuated with surgical revascularization
Sudden Heart Rate Reduction Upon Optogenetic Release of Acetylcholine From Cardiac Parasympathetic Neurons in Perfused Hearts
The balance of sympathetic and parasympathetic tone provides exquisite control of heart rate and contractility and has also been shown to modulate coronary flow and inflammation. Understanding how autonomic balance is altered by cardiac disease is an active area of research, and developing new ways to control this balance provides insights into disease therapies. However, achieving acute neuron-specific stimulation of autonomic neurons can be difficult in experiments that measure the acute effects of nerve stimulation on the heart. Conventional electrical and pharmacological approaches can be spatially and temporally non-selective. Cell-specific expression of light-activated channels (channelrhodopsin, ChR2) is a powerful approach that enables control of the timing and distribution of cellular stimulation using light. We present such an optogenetic approach where parasympathetic cardiac neurons are selectively photoactivated at high temporal precision to initiate cholinergic-mediated slowing of heart rate. Mice were crossbred to express ChR2 in peripheral cholinergic neurons using Cre-Lox recombination driven by a choline acetyltransferase (ChAT) promoter. Hearts from adult mice were excised, perfused, and the epicardium was illuminated (peak 460–465 nm) to photoactivate ChR2. In one set of studies, hearts were illuminated using a large-field LED light source. In other studies, a micro LED was placed on the right atrium to selectively illuminate the junction of the superior vena cava (SVC) and right atrium. The ECG was acquired before, during, and after tissue illumination to measure changes in heart rate. Upon illumination, hearts exhibited sudden and dramatic reductions in heart rate with restoration of normal heart rate after cessation of illumination. Delays in atrioventricular conduction were also observed. Heart rate reductions at the highest irradiance levels were similar to heart rate reductions caused by application of bethanechol (10 μM) or acetylcholine (800 μM). Atropine (50 nM) completely blocked the effect of ChR2 photoactivation, confirming cholinergic mediation. Optogenetic activation of intrinsic parasympathetic neurons reduced heart rate in an immediate, dose-dependent fashion, resembling the slowing of sinus rate in response to acetylcholine. Our results demonstrate a new approach for controlling parasympathetic modulation of cardiac function by selectively activating the endogenous release of acetylcholine from intrinsic cardiac cholinergic neurons.Key Message: Optogenetic photoactivation of intrinsic cardiac neurons provides immediate, tissue-specific stimulation with minimal cross-reactivity. Our results demonstrate that selective expression of channelrhodopsin within cardiac cholinergic neurons enables photoactivated release of acetylcholine, thereby instantaneously slowing sinus rate and altering atrioventricular conduction. This provides for in-depth examination of the endogenous interplay between cardiac autonomic neurons and the functional outcomes of downstream post-synaptic receptor activation
Functional status as a predictor of outcomes in open and endovascular abdominal aortic aneurysm repair
© 2016 Society for Vascular Surgery Background Functional status is a simple and rapidly assessable metric that may be used as a predictor for surgical outcomes. This study examined the association of functional status with short-term mortality after abdominal aortic aneurysm (AAA) repair in octogenarians to characterize the utility of functional status as a means of preoperative risk assessment. Methods All patients who underwent endovascular and open AAA repair from 2002 to 2010 within the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database were identified. Functional status, defined as an ordinal scale from 1 to 3 (1, independent; 2, partially dependent; 3, totally dependent), was examined using multivariate regression models with 30-day mortality as the primary outcome. For the purpose of analysis, this 3-point scale was converted into a binomial scale of function, with “normal” including 1 (completely independent) and “abnormal” including 2 or 3 (partially to totally dependent). Results We identified 9030 patients who underwent AAA repair (46.6% open and 53.4% endovascular). Mortality at 30 days was 2.8% for the entire cohort (4.2% open, 1.7% endovascular; P \u3c .001). There were 1340 patients aged ≥80 years, of which 67.3% underwent endovascular AAA repair. Among all age groups, functional status was a significant predictor of 30-day mortality (\u3c80 years, P \u3c .001; ≥80 years, P \u3c .001). The ≥80 cohort with abnormal function status also demonstrated increased operative mortality (P = .002), length of stay (P = .001), and incidence of pulmonary complications (P = .025) compared with the cohort with normal functional status. Multivariate logistic regression demonstrated that within the ≥80-year-old cohort, only functional status remained a significant predictor of mortality (P \u3c .001). In addition, the strength of the association between functional status and mortality was greater in the older cohort than in the younger one (Cox regression hazard ratio: 3.13 vs 2.18). Conclusions Functional status is a simple and rapidly applicable predictor of mortality within AAA patients and may be a useful tool to help preoperatively risk-stratify elderly patients presenting with AAA in need of repair. Further studies are needed to understand how best to apply these data to the clinical setting to guide preoperative decision making
A modified activity protocol for claudication
© 2018 EDIZIONI MINERVA MEDICA. BACKGROUND: We propose the use of a monitored step tracking device, the FitBit® to supplant supervised exercise therapy (SET) programs to facilitate improvement in walking distance in veteran claudicators. METHODS: In this prospective study, we enrolled forty-nine patients with clinical evidence of lower extremity claudication in a six-month walking program. Each patient was given a FitBit® device to track daily number of steps. Patients were seen in clinic monthly to collect data and discuss walking goals. Surveys at the beginning and end of each study assessed patient perception of changes in walking distance as well as symptoms. The primary outcome was monthly distance walked. Changes over time in each outcome variables were examined using a random effects mixed model. RESULTS: In the first month, the adjusted mean number of steps per day was 3492 (95% CI: 2661-4322). By month 5, this had increased to 4502 (3636-5367) (P=0.0007). Twenty-eight patients used the tracker at least for 1 month, while 21 (43%) did not. Being bothered by symptoms was the only patient variable that was significantly associated with use of the FitBit®. Those who used the tracker tended to be younger, heavier, more active, and were more likely to have diabetes. CONCLUSIONS: In the veteran population, the use of a monitored step tracking device such as the FitBit® is a potentially effective strategy to improve walking distance in claudicators particularly in those with mild symptoms. Additional investigation is needed to determine which patients will benefit most from this walking protocol