Lipid Lowering in "Very High Risk" Patients Undergoing Coronary Artery Bypass Surgery and Its Projected Reduction in Risk for Recurrent Vascular Events: A Monte Carlo Stepwise Simulation Approach.

ABSTRACT: 2018 AHA guidelines provide criteria to identify patients at very high risk (VHR) for adverse vascular events and recommend an low density lipoprotein-C (LDL-C) level <1.8 mmol/L. Data regarding the 10-year risk for adverse vascular events in coronary artery bypass grafting (CABG) patients at VHR and the need for nonstatin therapies in the VHR cohort are limited. We queried a national cohort of CABG patients to answer these questions. The projected reduction of LDL-C from stepwise escalation of lipid-lowering therapy (LLT) was simulated; Monte Carlo methods were used to account for patient-level heterogeneity in treatment effects. Data on preoperative statin therapy and LDL-C levels were obtained. In the first scenario, all eligible patients not at target LDL-C received high-intensity statins, followed by ezetimibe and then alirocumab; alternatively, bempedoic acid was also used. The 10-year risk for an adverse vascular event was estimated using a validated risk score. Potential risk reduction was estimated after simulating maximal LLT. Before CABG, 8948 of 27,443 patients (median LDL-C 85 mg/dL) were at VHR. In the whole cohort, 31% were receiving high-intensity statins. With stepwise LLT escalation, the proportion of patients at target were 60%, 78%, 86%, and 97% after high-intensity statins, ezetimibe, bempedoic acid, and alirocumab, respectively. The projected 10-year risk to suffer a vascular event reduced by 4.6%. A large proportion of CABG patients who are at VHR for vascular events fail to meet 2018 AHA LDL-C targets. A stepwise approach, particularly with the use of bempedoic acid, can significantly reduce the need for more expensive proprotein convertase subtilisin kexin 9 inhibitors.

Outcomes of coronary artery bypass grafting in patients with heart failure with a midrange ejection fraction.

BACKGROUND: Coronary artery bypass grafting (CABG) improves survival in patients with heart failure and severely reduced left ventricular systolic function (LVEF). Limited data exist regarding adverse cardiovascular event rates after CABG in patients with heart failure with midrange ejection fraction (HFmrEF; LVEF > 40% and < 55%). METHODS: We analyzed data on isolated CABG patients from the Veterans Affairs national database (2010-2019). We stratified patients into control (normal LVEF and no heart failure), HFmrEF, and heart failure with reduced LVEF (HFrEF) groups. We compared all-cause mortality and heart failure hospitalization rates between groups with a Cox model and recurrent events analysis, respectively. RESULTS: In 6533 veterans, HFmrEF and HFrEF was present in 1715 (26.3%) and 566 (8.6%) respectively; the control group had 4252 (65.1%) patients. HFrEF patients were more likely to have diabetes mellitus (59%), insulin therapy (36%), and previous myocardial infarction (31%). Anemia was more prevalent in patients with HFrEF (49%) as was a lower serum albumin (mean, 3.6 mg/dL). Compared with the control group, a higher risk of death was observed in the HFmrEF (hazard ratio [HR], 1.3 [1.2-1.5)] and HFrEF (HR, 1.5 [1.2-1.7]) groups. HFmrEF patients had the higher risk of myocardial infarction (subdistribution HR, 1.2 [1-1.6]; P = .04). Risk of heart failure hospitalization was higher in patients with HFmrEF (HR, 4.1 [3.5-4.7]) and patients with HFrEF (HR, 7.2 [6.2-8.5]). CONCLUSIONS: Heart failure with midrange ejection fraction negatively affects survival after CABG. These patients also experience higher rates myocardial infarction and heart failure hospitalization.

Off-Pump Coronary Artery Bypass Grafting: Department of Veteran Affairs' Use and Outcomes.

Background Coronary artery bypass can be performed off pump (OPCAB) without cardiopulmonary bypass. However, trends over time for OPCAB versus on-pump (ONCAB) use and long-term outcome has not been reported, nor has their long-term outcome been compared. Methods and Results We queried the national Veterans Affairs database (2005-2019) to identify isolated coronary artery bypass procedures. Procedures were classified as OPCAB on ONCAB using the as-treated basis. Trend analyses were performed to evaluate longitudinal changes in the preference for OPCAB. The median follow-up period was 6.6 (3.5-10) years. An inverse probability weighted Cox model was used to compare all-cause mortality between OPCAB and ONCAB. From 47 685 patients, 6759 (age 64±8 years) received OPCAB (14%). OPCAB usage declined from 16% (2005-2009) to 8% (2015-2019). Patients with triple vessel disease who received OPCAB received a lower mean number of grafts (2.8±0.8 versus 3.2±0.8; P<0.01). The ONCAB 5-, 10-, and 15-year survival rates were 82.9% (82.5-83.3), 60.4% (59.8-61.1), and 37.2% (36.1-38.4); correspondingly, OPCAB rates were 80.7% (79.7-81.7), 57.4% (56-58.7), and 34.1% (31.7-36.6) (P<0.01). OPCAB was associated with increased risk-adjusted all-cause mortality (hazard ratio, 1.15 [1.13-1.18]; P<0.01) and myocardial infarction (incident rate ratio, 1.16 [1.05-1.28]; P<0.01). Conclusions Over 15 years, OPCAB use declined considerably in Veterans Affairs medical centers. In Veterans Affairs hospitals, late all-cause mortality and myocardial infarction rates were higher in the OPCAB cohort.

Revascularization in ischaemic heart failure with preserved ejection fraction: a nationwide cohort study.

AIMS: Despite the common occurrence of coronary artery disease (CAD) and heart failure (HF) with preserved ejection fraction (HFpEF), there is limited evidence to guide revascularization. METHODS AND RESULTS: We investigated the long-term outcomes of coronary artery bypass grafting (CABG) in patients with HF and significant CAD across the spectrum of ejection fraction, using a large national cohort of patients from the Veteran Affairs (VA) Medical Centers in the US. Patients with HF were stratified into groups, HFpEF, HF with mid-range ejection fraction (HFmrEF), and HF with reduced ejection fraction (HFrEF) and compared to patients with no preoperative HF. We analysed 10 396 patients. Despite an increased hazard in the first year following revascularization, the long-term survival (median follow-up 6.6 years; interquartile range 3.7-10.1) of HFpEF post-CABG was similar to controls (hazard ratio 0.85, 95% confidence interval 0.68-1.06), but survival progressively declined with HFmrEF and HFrEF. Similar trends were seen with recurrent HF hospitalization with lower risk with baseline HFpEF (43.9 ± 6.9/100 patient-years) compared to HFmrEF (65.9 ± 3.8/100 patient-years) and HFrEF (93.4 ± 4.8/100 patient-years). Although HFpEF patients had lower mortality and HF hospitalization post-CABG compared to patients with a lower ejection fraction, they experienced the highest rates of future myocardial infarction. CONCLUSION: Although HFpEF patients with CAD have greater short-term risk post-CABG, their long-term survival is comparable to controls. However, they are at increased risk for HF hospitalizations and myocardial infarction. These data support the safety of CABG in HFpEF patients and suggest continuum of mortality risk for ischaemic HF when stratified by baseline ejection fraction before revascularization.

Adverse events after coronary artery bypass grafting in patients with preoperative metabolic syndrome: A 10-year follow-up of the Veterans Affairs Database.

INTRODUCTION: Data regarding 10-year survival and adverse cardiovascular events in patients with metabolic syndrome (MET) after coronary artery bypass grafting (CABG) is limited. METHODS: We compared 10-year events rates for veterans undergoing isolated CABG (January 1, 2005, to December 31, 2014, follow-up October 31, 2019) stratified by presence of metabolic syndrome (MET+) versus without (MET-). A multivariable weighted Cox model was used to analyze all-cause mortality. Competing risk analysis was used to calculate cumulative event rates for congestive heart failure, myocardial infarction, and cerebrovascular events. The Fine-Gray subhazard model was used to determine adjusted association of MET with myocardial infarction and stroke. Congestive heart failure was modeled as a recurrent-event analysis. RESULTS: Nationally, 9615 adults (median age, 60 years; 98.9% men) underwent isolated coronary artery bypass grafting at 41 centers); among them, 3121 out of 9615 (32.5%) had MET. The prevalence of MET increased from (27.88% in 2005 to 34.02% in 2014; P = .02). MET+ group members were likely younger (median age, 63 vs 64 years; P < .01), White (72% vs 68%), and had more peripheral vascular disease (30% vs 28%; P = .04). Multivessel (72% vs 70%; P = .23) and multiarterial (4% vs 4%; P = .14) grafting was performed equally. With a median follow-up of 6.5 years, survival was similar (P = .26); however, MET was associated with higher risks for myocardial infarction (21% vs 16%; hazard ratio, 1.3; P < .01) and recurrent admissions for congestive heart failure. CONCLUSIONS: Patients with metabolic syndrome undergoing coronary artery bypass grafting have higher 10-year cardiovascular event rates.

Pre-operative glycaemic control and long-term survival in diabetic patients after coronary artery bypass grafting.

OBJECTIVES: We analysed the Veteran Affairs data to evaluate the association of pre-operative glycated haemoglobin (HbA1c) and long-term outcome after isolated coronary artery bypass grafting (CABG). METHODS: Veterans with diabetes mellitus and isolated CABG (2006-2018) were divided into 4 groups (I: HbA1c <6.5%, II: HbA1c 6.5-8, III 8-10% and IV: HbA1c >10%). The relationship of pre-operative HbA1c and long-term survival was evaluated with a multivariable Cox proportional hazards model and reported as hazard ratios (HR). The cumulative incidence of secondary end-points [myocardial infarction (MI) and repeat revascularization (percutaneous intervention)] for each group was modelled as competing events with cause-specific Cox proportional hazards models. RESULTS: Overall, 16 190 patients (mean age 64.9 years, male 98%; insulin dependent 53%) with diabetes mellitus underwent isolated CABG. We observed 19.4%, 45.4%, 27% and 8.2% patients in groups I, II, III and IV, respectively. Patients with HbA1c >10% were the youngest (mean age 60.9 years) and had high rates of Insulin dependence (78%). In patients with HbA1c >10%, improvement in levels was observed in 76%. The median follow-up observed was 5.8 (3.2-8.8) years. Compared to the study mean HbA1c (7.3%), mortality rate increased with HbA1c levels >8%, and especially with pre-operative HbA1c levels >9%. Compared to patients with HbA1c <8%, HbA1c 8-10% and >10% were associated with increased MI (HR 1.24 and HR 1.39, respectively) and need for reintervention (HR 1.20 and HR 1.24, respectively). CONCLUSIONS: In patients undergoing CABG, pre-operative HbA1c >8% is associated with the increased risk of mortality and adverse cardiac events.

Home health care after discharge is associated with lower readmission rates for patients with acute myocardial infarction.

OBJECTIVE: We studied the utilization of home health care (HHC) among acute myocardial infarction (AMI) patients, impact of HHC on and predictors of 30-day readmission. METHODS: We queried the National Readmission Database (NRD) from 2012 to 2014identify patients with AMI discharged home with (HHC+) and without HHC (HHC-). Linkage provided in the data identified patients who had 30-day readmission, our primary end-point. The probability for each patient to receive HHC was calculated by a multivariable logistic regression. Average treatment of treated weights were derived from propensity scores. Weight-adjusted logistic regression was used to determine impact of HHC on readmission. RESULTS: A total of 406 237 patients with AMI were discharged home. Patients in the HHC+ cohort (38 215 patients, 9.4%) were older (mean age 77 vs. 60 years P < 0.001), more likely women (53 vs. 26%, P < 0.001), have heart failure (5 vs. 0.5%, P < 0.001), chronic kidney disease (26 vs. 6%, P < 0.001) and diabetes (35 vs. 26%, P < 0.001). Patients readmitted within 30-days were older with higher rates of diabetes (RR = 1.4, 95% CI: 1.37-1.48) and heart failure (RR = 5.8, 95% CI: 5.5-6.2). Unadjusted 30-day readmission rates were 21 and 8% for HHC+ and HHC- patients, respectively. After adjustment, readmission was lower with HHC (21 vs. 24%, RR = 0.89, 95% CI: 0.82-0.96; P < 0.001). CONCLUSION: In the United States, AMI patients receiving HHC are older and have more comorbidities; however, HHC was associated with a lower 30-day readmission rate.

Sentinel Contributions of US Department of Veterans Affairs Surgeons in Shaping the Face of Health Care.

The vast accomplishments of the US Department of Veterans Affairs (VA) during the past century have contributed to the advancement of medicine and benefited patients worldwide. This article highlights some of those accomplishments and the advantages in the VA system that promulgated those successes. Through its affiliation with medical schools, its formation of a structured research and development program, its Cooperative Studies Program, and its National Surgical Quality Improvement Program, the VA has led the world in the progress of health care. The exigencies of war led not only to the organization of VA health care but also to groundbreaking, landmark developments in colon surgery; surgical treatments for vascular disease, including vascular grafts, carotid surgery, and arteriovenous dialysis fistulas; cardiac surgery, including implantable cardiac pacemaker and coronary artery bypass surgery; and the surgical management of many conditions, such as hernias. The birth of successful liver transplantation was also seen within the VA, and countless other achievements have benefited patients around the globe. These successes have created an environment where residents and medical students are able to obtain superb education and postgraduate training and where faculty are able to develop their clinical and academic careers.

Home health care visits may reduce the need for early readmission after coronary artery bypass grafting.

BACKGROUND: The Center for Medicaid and Medicare Services penalizes hospitals with high readmission rates after coronary artery bypass grafting (CABG). Home health care (HHC) is a proven discharge support tool. We performed a propensity-matched analysis to determine impact of HHC on readmissions after CABG. METHODS: We queried the National Readmissions Database (January 2012-December 2014) for patients undergoing isolated CABG discharged home with and without HHC. Primary end point was 30-day readmission. A well-balanced subset of patients with and without HHC was created with propensity matching. Weight-adjusted logistic regression was performed to determine impact of HHC on readmissions after CABG. RESULTS: In our study, 204,184 patients (mean age. 64 years; 22% female) were discharged home after CABG; 86,206 (42%) received HHC. Old age (66 vs 63 years; P < .01), diabetes (46% vs 41%; P < .001), COPD (21% vs 18%; P < .01), peripheral arterial disease (14% vs 11%; P < .001), and chronic kidney disease (2% vs 1.5%; P = .01) were factors associated with HHC. With nearest-neighbor 1:1 matching without replacement, we identified 66,610 patient pairs (unweighted) for further analysis. Readmission occurred in 11.1% and 12.5% of patients with and without HHC, respectively. After adjustment for 21 clinical covariates, use of HHC (odds ratio, 0.816; 95% confidence interval, 0.808-0.823) led to significantly lower readmission rates (P < .001). CONCLUSIONS: HHC after coronary artery bypass surgery is more often provided to women, older patients, and those with diabetes mellitus, peripheral arterial disease, and chronic lung or kidney dysfunction. HHC appears to be associated with reduced rates of early readmission.

Safety-net hospitals versus non-safety centers and clinical outcomes after trans-catheter aortic valve replacement.

OBJECTIVE: To compare post-procedural outcomes of trans-catheter valve replacement (TAVR) among safety-net (SNH) and non-safety net hospitals (non-SNH). BACKGROUND: SNH treat a large population of un-insured and low income patients; prior studies report worse outcome at these centers. Results of TAVR at these centers is limited. METHODS: Adults undergoing TAVR at hospitals in the US participating in the National In-patient sample (NIS) database from January 2014 to December 2015 were included. A 1:1 propensity-matched cohort of patients operated at SNH and non-SNH institutions was analyzed, on the basis of 16 demographic and clinical co-variates. Main outcome was all-cause post-procedural mortality. Secondary outcomes included stroke, acute kidney injury and length of post-operative stay. RESULTS: Between 2014 and 2015, 41,410 patients (mean age 80 ± 0.11 years, 46% female) underwent TAVR at 731 centers; 6,996 (16.80%) procedures were performed at SNH comprising 135/731 (18.4%) of all centers performing TAVR. SNH patients were more likely to be female (49% vs. 46%, p < .001); admitted emergently (31% vs. 21%; p < .001; at the lowest quartile for household income (25% % vs. 20%; p < .001) and from minorities (Blacks 5.9% vs. 3.9%; Hispanic 7.2% vs. 3.2%).Adjusted logistic regression was performed on 6,995 propensity-matched patient pairs. Post-procedural mortality [OR 0.99(0.98-1.007); p = .43], stroke [OR 1.009(0.99-1.02); p = .08], acute kidney injury [OR 0.99(0.96-1.01); p = .5] and overall length of stay (6.9 ± 0.1 vs. 7.1 ± 0.2 days; p = .57) were comparable in both cohorts. CONCLUSION: Post-procedural outcomes after TAVR at SNH are comparable to national outcomes and wider adoption of TAVR at SNH may not adversely influence outcomes.

Emerging trends in mediastinitis: National Veterans Health Administration experience with methicillin-resistant Staphylococcus aureus prevention.

OBJECTIVES: Perioperative bacterial decolonization and prophylactic antibiotic therapy at the Veterans Affairs Health Care System have changed over the past decade. Our objectives were to identify associated changes in the microbiology of mediastinitis and to perform a contemporary survival analysis in patients with mediastinitis after isolated coronary artery bypass grafting procedure. METHODS: From January 2006 to December 2015, 45,323 consecutive patients underwent coronary artery bypass grafting at 83 medical centers. The Veterans Affairs Health Care System nationwide administrative database was queried to identify patients with postoperative mediastinitis and obtain patient-level data. Simple descriptive statistics and multivariable logistic regression were used to analyze microbiologic data and identify risk factors for infection. Poisson regression was used to determine yearly incidence estimates. Cox proportional hazard model identified predictors of long-term survival from date of operation. RESULTS: During the study period, 348 patients (0.78%) developed postoperative mediastinitis-with a stable rate of incidence (Cochrane-Armitage test, P = .69). Of patients with microbiologic data, 75.5% of infections (n = 188) were caused by gram-positive and 24.5% (n = 61) gram-negative organisms. The incidence of methicillin-resistant Staphylococcus aureus mediastinitis decreased during the study period (Cochrane-Armitage test, P = .013). Gram-negative mediastinitis occurred earlier than gram-positive mediastinitis (median, 15.0 vs 25.0 days; P < .0001). Patients with mediastinitis did not have increased 30-day mortality (2.0% vs 1.9%; P = .9), but had worse long-term survival compared with uninfected patients (P < .0001). CONCLUSIONS: The incidence of methicillin-resistant S aureus mediastinitis has decreased over the past decade. Gram-negative bacteria are responsible for 1 in 4 cases of mediastinitis and infection is diagnosed earlier in the postoperative period than gram-positive mediastinitis. These findings highlight the need for efforts to prevent gram-negative and methicillin-susceptible S aureus mediastinitis.

Distress Screening and Management in an Outpatient VA Cancer Clinic: A Pilot Project Involving Ambulatory Patients Across the Disease Trajectory.

Screening all patients for distress addressed practical, psychosocial, physical, and spiritual needs does not seem to be burdensome for patients or providers at an outpatient cancer center.

Development and Implementation of a Veterans' Cancer Survivorship Program.

The integration of a cancer survivorship program and coordination of care with primary care providers in community settings is essential to address veteran cancer survivors' unique needs and to meet national guidelines.

Unusual cause of acute mitral regurgitation: idiopathic hypereosinophilic syndrome.

Idiopathic hypereosinophilic syndrome (HES) is a rare multisystem condition characterized by dysregulated overproduction of eosinophils. Cardiac involvement in HES is characterized by necrosis from infiltration of eosinophils and thrombus formation and, in the late stage, by fibrosis and chronic valvular regurgitation. We report a very unusual presentation of idiopathic HES with acute mitral regurgitation due to papillary muscle rupture. The transesophageal echocardiogram was suggestive of a flail posterior leaflet and suspicious for endocarditis. Intraoperatively, papillary muscle rupture was seen and the patient underwent mitral valve replacement. The pathologic examination of the valve revealed eosinophilic infiltration of the papillary muscle. The patient was treated with steroids and responded well clinically.

Bio-inspired, efficient, artificial lung employing air as the ventilating gas.

Artificial lungs have recently been utilized to rehabilitate patients suffering from lung diseases. However, significant advances in gas exchange, biocompatibility, and portability are required to realize their full clinical potential. Here, we have focused on the issues of gas exchange and portability and report a small-scale, microfabricated artificial lung that uses new mathematical modeling and a bio-inspired design to achieve oxygen exchange efficiencies much larger than current devices, thereby enabling air to be utilized as the ventilating gas. This advancement eliminates the need for pure oxygen required by conventional artificial lung systems and is achieved through a device with feature sizes and structure similar to that in the natural lung. This advancement represents a significant step towards creating the first truly portable and implantable artificial lung systems for the ambulatory care of patients suffering from lung diseases.

Cardioplegia prevents ischemia-induced transcriptional alterations of cytoprotective genes in rat hearts: a DNA microarray study.

BACKGROUND: Energy conservation and calcium homeostasis contribute to myocardial protection provided by hyperkalemic cardioplegia during ischemia. Complimenting these established mechanisms of protection, previous work suggested that activation of cytoprotective signaling pathways also contributes to reduced injury with cardioplegia. We proposed that cardioplegia would recruit cytoprotective pathways and investigated the transcriptional response of the heart after cardioplegia-protected ischemia compared with that after ischemia alone. METHODS: Isolated perfused rat hearts underwent 40 minutes of global ischemia alone or with St Thomas cardioplegia, followed by 120 minutes of reperfusion. The expression profiles of isolated RNA were determined by using Affymetrix microarrays and assessed by comparing cardioplegia-protected hearts and hearts undergoing unprotected ischemia with time-matched control hearts. The content of selected proteins was assessed by means of immunoblotting. RESULTS: Cardioplegia preserved the expression of multiple genes involved in carbohydrate and fatty acid metabolism, glycolysis, and electron transport compared with ischemia alone. The expression of the sodium-calcium exchanger and ryanodine receptor was preserved in line with the ability of cardioplegia to decrease calcium overload. The expression of multiple cytoprotective molecules, including protein-tyrosine kinase, calcineurin B, p38 mitogen-activated protein kinase, voltage-dependent anion channel, protein kinase C , heat shock protein 70, and manganese superoxide dismutase all showed decreased expression in ischemia but were preserved to near nonischemic levels by cardioplegia. CONCLUSION: Cardioplegia during ischemia maintained an expression profile similar to that seen in nonischemic hearts for genes involved in energy conservation, calcium homeostasis, and cytoprotective pathways, whereas ischemia alone did not. Exposing the transcriptional differences in cytoprotective genes during untreated and cardioplegia-treated ischemia provides valuable insight into an additional mechanism of cardioprotection induced by cardioplegia.

Cardioprotection by St Thomas' solution is mediated by protein kinase C and tyrosine kinase.

BACKGROUND: Intracellular signaling pathways, specifically the activation of protein kinase C and tyrosine kinase, are essential to the cardioprotection of ischemic preconditioning. We proposed that activation of PKC and TK contribute to the myocardial protection of St. Thomas' No. 2 cardioplegia solution (STC). MATERIALS AND METHODS: Isolated rat hearts were exposed to 40 min of global ischemia followed by 120 min of reperfusion. Before ischemia, hearts received no treatment (control; n = 7), STC (n = 7), phorbol 12-myristate 13-acetate (PMA; n = 6), PMA + chelerythrine (n = 6), anisomycin (n = 6), anisomycin + genistein (n = 7), STC + chelerythrine (n = 7), STC + genistein (n = 7), PMA + genistein (n = 7) or anisomycin + chelerythrine (n = 7). Left ventricular developed pressure (LVDP) recovery, myocardial infarct size, and lactate dehydrogenase release were measured. RESULTS: STC as well as PMA (protein kinase C activator) and anisomycin (tyrosine kinase activator) significantly reduced infarct size (6.9 +/- 2.9%, 9.6 +/- 2.1%, 14.0 +/- 4.4%) compared with controls (42.4 +/- 2.9%, P < 0.05). The infarct reduction of PMA and anisomycin were blocked by their inhibitors chelerythrine and genistein, respectively. Both chelerythrine (29.2 +/- 4.1%, P < 0.05) and genistein (40.4 +/- 4.3%, P < 0.05) attenuated the reduction of infarct size provided by STC. The recovery of LVDP improved with STC, PMA and anisomycin (72.6 +/- 1.4%, 60.4 +/- 4.7%, 57.2 +/- 4.6%) compared with control (33.8 +/- 3.6%, P < 0.05). Addition of chelerythrine or genistein to STC impaired recovery of LVDP (52.3 +/- 4.4%, 35.1 +/- 2.5%, P < 0.05) compared with STC treatment. CONCLUSION: Administration of the pharmacologic inhibitors chelerythrine and genistein blunts the cardioprotection caused by STC treatment.

Aortomyoplasty: hemodynamics and comparison to the intraaortic balloon pump.

BACKGROUND: Aortomyoplasty (AMP), a procedure in which the latissimus dorsi muscle (LDM) is wrapped around the aorta and stimulated during diastole, is a potential method of chronic counterpulsation. Counterpulsation by the intraaortic balloon pump (IABP) is a proven treatment for ischemic coronary syndrome and heart failure but cannot be used chronically. This study examined the long-term potential of a unique AMP configuration and compared its performance to the IABP. MATERIALS AND METHODS: AMP was done using a wringer configuration (AMP-W) in nine dogs. Six and 12 months later, acute hemodynamic augmentation was evaluated by measuring differences in mean diastolic aortic pressure (mDAP), peak left ventricular pressure (pLVP), and the endocardial viability ratio (EVR) between stimulated and unstimulated beats. RESULTS: The diastolic augmentation obtained by AMP-W at 6 months and by AMP-W and IABP at 12 months was statistically significant. Additionally, the enhancements in EVR (16.1 +/- 4.3%), mDAP (8.6 +/- 2.5%), and pLVP (-1.8 +/- 1.0%) at 6 months were similar to those in EVR (19.1 +/- 5.2%), mDAP (13.1 +/- 3.6%), and pLVP (-0.8 +/- 1.3%) at 12 months. Most importantly, the augmentation obtained by AMP-W at 12 months was similar to that of the IABP: EVR (17.1 +/- 5.9%), mDAP (13.4 +/- 6.7%), and pLVP (-1.5 +/- 0.8%). CONCLUSIONS: AMP-W is a safe, robust procedure, capable of providing counterpulsation equivalent to the IABP, 12 months following surgery. The potential for AMP-W to offer chronic counterpulsation and to benefit the ischemic heart should be investigated further.

Circulatory benefits of diastolic counterpulsation in an ischemic heart failure model after aortomyoplasty.

OBJECTIVE: Aortomyoplasty is an experimental surgical procedure in which the latissimus dorsi muscle is wrapped around the thoracic aorta and stimulated to contract during diastole, providing diastolic counterpulsation. We hypothesized that aortomyoplasty could improve cardiac function in a chronic ischemic heart failure model, similar to the improvement seen with the intra-aortic balloon pump. METHODS: Six dogs (25-30 kg) successfully underwent aortomyoplasty followed by serial coronary microembolization. Ejection fraction decreased from 63.5% to 36.5%. Two weeks after the final microembolization, the muscle was conditioned for 4 months to achieve fatigue resistance. One year after aortomyoplasty, hemodynamic studies during 1 hour of aortomyoplasty and 1 hour of intra-aortic balloon counterpulsation determined mean diastolic aortic pressure, peak left ventricular pressure, and endocardial viability ratio for assisted and unassisted beats. Cardiac output, stroke volume, and parameters of cardiac function were also measured. RESULTS: Endocardial viability ratio increased by 23.8% +/- 7.9% (P =.001) with aortomyoplasty counterpulsation and by 22.7% +/- 12.9% (P =.021) with the intra-aortic balloon pump. Both aortomyoplasty and the intra-aortic balloon pump significantly increased mean diastolic aortic pressure and reduced peak left ventricular pressure. Improvements in cardiac function with aortomyoplasty and the intra-aortic balloon pump were similar. Cardiac output increased from 2.61 +/- 0.88 to 3.07 +/- 1.06 L/min (P =.006), and index of afterload decreased from 5.4 +/- 1.4 to 4.8 +/- 1.4 mm Hg/mL (P =.02) during 1 hour of aortomyoplasty counterpulsation. CONCLUSION: One year after the procedure, aortomyoplasty counterpulsation provided diastolic augmentation and improved cardiac performance similar to the improvement provided by the intra-aortic balloon pump in a chronic ischemic heart failure model. Aortomyoplasty has the potential to benefit patients with ischemic heart disease refractory to current therapies.

Reducing Mortality Among Elderly Patients Undergoing Urgent Surgical Revascularization for Acute Myocardial Infarction.

INTRODUCTION: Elderly patients undergoing coronary bypass surgery after acute myocardial infarction represent a distinct, high risk subgroup. We sought to identify independent risk factors for mortality in a series of patients operated on in our hospital. METHODS: The case records of 499 consecutive patients greater than 70 years were identified, and 94 of these patients underwent urgent/emergent coronary bypass surgery within 7 days of acute myocardial infarction. Patients received either cold (4°C) or tepid (32°C) cardioplegia for myocardial protection. RESULTS: Mortality for the tepid cardioplegia group was 0/33, and the mortality for the cold cardioplegia group was 12/61 (0% vs. 20%, p equals 0.003). Multivariate analysis demonstrated left ventricular dysfunction and cold blood cardioplegia to be independent predictors of mortality. CONCLUSION: The type of myocardial protection technique is a significant predictor of mortality, and tepid cardioplegia may provide significant advantages to this high risk patient population.