Antineutrophil Cytoplasmic Antibody Vasculitis after Coronary Artery Bypass Grafting.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a group of rare autoimmune disorders associated with the presence of ANCA autoantibodies. We present the first reported case of acute ANCA-associated vasculitis following coronary artery bypass grafting in a 74-year-old male presenting on postoperative day 13 with shortness of breath, orthopnea, and acute kidney injury. Renal biopsy ultimately showed focal necrotizing and crescentic glomerulonephritis, and the patient was successfully managed with corticosteroids and outpatient rituximab. This rare case highlights the importance of having an expanded differential for uncommon causes of cardiovascular disease and unexpected outcomes after coronary artery bypass grafting.

Patients with uncontrolled hypertension subjected to cardiopulmonary bypass have altered coronary vasomotor responses to serotonin.

BACKGROUND: We previously found that cardioplegic arrest and cardiopulmonary bypass are associated with altered coronary arteriolar response to serotonin in patients undergoing cardiac surgery. In this study, we investigated the effects of hypertension on coronary microvascular vasomotor tone in response to serotonin and alterations in serotonin receptor protein expression in the setting of cardioplegic arrest and cardiopulmonary bypass. METHODS: Coronary arterioles were dissected from harvested pre- and post-cardioplegic arrest and cardiopulmonary bypass right atrial tissue samples of patients undergoing cardiac surgery with normotension, well-controlled hypertension, and uncontrolled hypertension. Vasomotor tone was assessed by video-myography, and protein expression was measured with immunoblotting. RESULTS: Pre-cardioplegic arrest and cardiopulmonary bypass, serotonin induced moderate relaxation responses of coronary arterioles in normotension and well-controlled hypertension patients, whereas serotonin caused moderate contractile responses in uncontrolled hypertension patients. Post-cardioplegic arrest and cardiopulmonary bypass, serotonin caused contractile responses of coronary arterioles in all 3 groups. The post-cardioplegic arrest and cardiopulmonary bypass contractile response to serotonin was significantly higher in the uncontrolled hypertension group compared with the normotension or well-controlled hypertension groups (P < .05). Pre-cardioplegic arrest and cardiopulmonary bypass, expression of the serotonin 1A receptor was significantly lower in the uncontrolled hypertension group compared with the well-controlled hypertension and normotension groups (P = .01 and P < .001). Serotonin 1B receptor expression was higher in the uncontrolled hypertension group compared with the normotension or well-controlled hypertension groups post-cardioplegic arrest and cardiopulmonary bypass (P = .03 and P = .046). CONCLUSION: Uncontrolled hypertension is associated with an increased coronary contractile response of coronary microvessels to serotonin and altered serotonin receptor protein expression after cardioplegic arrest and cardiopulmonary bypass. These findings may contribute to a worse postoperative coronary spasm and worsened recovery of coronary perfusion in patients with uncontrolled hypertension after cardioplegic arrest and cardiopulmonary bypass and cardiac surgery.

History of Psychoactive Medication a Risk Factor for Neurocognitive Decline After Cardiac Surgery.

INTRODUCTION: Neurocognitive decline (NCD) is a common complication after cardiac surgery with implications for outcomes and quality of life. Identifying risk factors can help surgeons implement preventative measures, optimize modifiable risk factors, and counsel patients about risk and prognosis. METHODS: Prospective cohort study at a single academic center. 104 patients planned to undergo cardiac surgery were enrolled. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to measure neurocognitive function preoperatively, on postoperative day four, and postoperative day 30. NCD is defined as a change in RBANS scaled score of < -8 from baseline to postoperative day 4. Patient charts were reviewed for medication history: beta-blockers, angiotensin-converting enzyme and angiotensin receptor blockers, calcium channel blockers, statins, oral hypoglycemic agents, and psychoactive medications. Charts were also reviewed to calculate postoperative opioid usage. RESULTS: NCD was detected in 42.9% of patients. Incidence of NCD was significantly higher in patients taking a psychoactive medication (56.8%) than patients not (31.9%), P < 0.03. There was no relationship between historical use of beta-blocker, calcium-channel blocker, statin, or oral hypoglycemic medications and incidence of NCD. Simple linear regression showed no relationship between change in RBANS total scaled score and opioid usage. There was no difference in incidence of NCD at 1 mo. CONCLUSIONS: Patients with a history of taking psychoactive medications prior to cardiac surgery have an increased risk of acute postoperative NCD.

Association Between Marijuana Use and Clinical Outcomes After Coronary Artery Bypass Grafting.

INTRODUCTION: Though marijuana use has been linked to an increase in heart failure admissions, no prior study has explored the association between its use and outcomes after coronary artery bypass grafting (CABG). This study examines the relationship between marijuana use and postoperative outcomes in CABG patients. METHODS: We utilized data from the National Inpatient Sample database from 2008 to 2018 for CABG patients ≥18 y old. Patients were divided into two groups based on marijuana use (abuse/dependency versus nonuse). Primary outcomes include in-hospital mortality, favorable discharge, and length of stay (LOS). Secondary outcomes include acute kidney injury (AKI), acute myocardial infarction (AMI), and transient ischemic attack (TIA)/stroke. A multivariable model, adjusted for confounding variables, was utilized for each outcome. RESULTS: A total of 343,796 patients met inclusion criteria for the study, 590 of which were marijuana users. In both marijuana user and nonuser groups, most patients were male and White with an average age of 56.0 and 66.3 y, respectively. There was a nonsignificant decreased odds of in-hospital mortality among marijuana users (odds ratio [OR] = 0.41, [0.141-1.124]). Marijuana users exhibited significantly decreased odds of home discharge (OR = 1.50, [1.24-1.81]), and increased odds of longer LOS (mean 10.4 d versus 9.8 d; OR = 1.14, [1.09-1.20]), AKI (OR = 1.40, [1.11-1.78]), AMI (OR = 1.56, [1.32-1.84]), and TIA/stroke (OR = 1.64, [1.21-2.22]). CONCLUSIONS: Marijuana use and dependency are associated with increased nonhome discharge, AKI, AMI, TIA/stroke, and longer LOS. Further studies are needed to delineate the pathophysiologic derangements that contribute to these unfavorable post-CABG outcomes.

Increased Coronary Contraction to Thromboxane A2 in Cardiac Surgery Patients With Poorly Controlled Hypertension.

INTRODUCTION: Cardioplegia and cardiopulmonary bypass (CP/CPB) alters coronary arteriolar response to thromboxane A2 (TXA2) in patients undergoing cardiac surgery. Comorbidities, including hypertension (HTN), can further alter coronary vasomotor tone. This study investigates the effects of HTN on coronary arteriolar response to TXA2 pre and post-CP/CPB and cardiac surgery. MATERIALS AND METHODS: Coronary arterioles pre and post-CP/CPB were dissected from atrial tissue samples in patients with no HTN (NH, n = 9), well-controlled HTN (WC, n = 12), or uncontrolled HTN (UC, n = 12). In-vitro coronary microvascular reactivity was examined in the presence of TXA2 analog U46619 (10-9-10-4M). Protein expression of TXA2 receptor in the harvested right atrial tissue samples were measured by immunoblotting. RESULTS: TXA2 analog U46619 induced dose-dependent contractile responses of coronary arterioles in all groups. Pre-CPB contractile responses to U46619 were significantly increased in microvessels in the UC group compared to the NH group (P < 0.05). The pre-CP/CPB contractile responses of coronary arterioles were significantly diminished post-CP/CPB among the three groups (P < 0.05), but there remained an increased contractile response in the microvessels of the UC group compared to the WC and NH groups (P < 0.05). There were no significant differences in U46619-induced vasomotor tone between patients in the NH and WC groups (P > 0.05). There were no differences in expression of TXA2R among groups. CONCLUSIONS: Poorly controlled HTN is associated with increased contractile response of coronary arterioles to TXA2. This alteration may contribute to worsened recovery of coronary microvascular function in patients with poorly controlled HTN after CP/CPB and cardiac surgery.

Effect of Patient Sex on Neurocognitive Decline after Cardiac Surgery.

BACKGROUND: Neurocognitive decline (NCD) is a common complication of cardiac surgery. Understanding risk factors helps surgeons counsel patients pre- and perioperatively about risk, prevention, and treatment. STUDY DESIGN: Patients undergoing cardiac surgery using cardiopulmonary bypass underwent pre- and postoperative neurocognitive testing. Neurocognitive data are presented as a change from baseline to either postoperative day 4 or to 1 month. The score is standardized with respect to age. RESULTS: Eighty-four patients underwent surgery and completed postoperative neurocognitive testing. There was no significant difference in baseline neurocognitive function. NCD was more common in female patients (71%) than male patients (26.4%) on postoperative day 4. By 1 month, the incidence of NCD is similar between female (15.0%) and male patients (14.3%). Of note, female patients differed from male patients in preoperative hematocrit, preoperative creatinine, and type of surgery. CONCLUSIONS: In the acute postoperative period, female patients are both more likely to experience NCD and experience a more severe change from baseline cognitive function. This difference between male and female patients resolves by the 1 month follow-up point. Female patients had a lower preoperative hematocrit and were more likely to receive intraoperative and perioperative blood transfusion. Lower preoperative hematocrit appears to mediate the difference in NCD between male and female patients.

Poorly controlled hypertension is associated with increased coronary myogenic tone in patients undergoing cardiac surgery with cardiopulmonary bypass.

OBJECTIVE: Cardioplegia and cardiopulmonary bypass dysregulate coronary vasomotor tone, which can be further affected by common comorbidities in patients undergoing cardiac surgery. This study investigates differences in coronary myogenic tone and vasomotor responses to phenylephrine before and after cardioplegia and cardiopulmonary bypass based on hypertension history. METHODS: Coronary arterioles before and after cardioplegia and cardiopulmonary bypass were dissected from atrial tissue samples in patients with no hypertension, well-controlled hypertension, or uncontrolled hypertension, as determined by documented history of hypertension, antihypertensive agent use, and clinical blood pressure measurements averaged over 1 year. Myogenic tone in response to stepwise increases in intraluminal pressure was studied between pressure steps. Microvascular reactivity in response to phenylephrine was assessed via vessel myography. Protein expression was measured with immunoblotting. RESULTS: Coronary myogenic tone was significantly increased in the uncontrolled hypertension group compared with the no hypertension and well-controlled hypertension groups before cardioplegia and cardiopulmonary bypass at higher intraluminal pressures, and after cardioplegia and cardiopulmonary bypass across all intraluminal pressures (P < .05). Contractile responses to phenylephrine were significantly enhanced in patients in the uncontrolled hypertension group compared with the well-controlled hypertension group before cardioplegia and cardiopulmonary bypass, and in the uncontrolled hypertension group compared with the no hypertension and well-controlled hyertension groups after cardioplegia and cardiopulmonary bypass (P < .05). There were no differences in myogenic tone or phenylephrine-induced reactivity between the no hypertension and well-controlled hypertension groups (P > .05). There was increased expression of phosphorylated protein kinase C alpha in the uncontrolled hypertension group after cardiopulmonary bypass compared with before cardiopulmonary bypass and increased phosphorylated extracellular signal-regulated kinase 1/2 in the uncontrolled hypertension compared with the no hypertension group after cardiopulmonary bypass (P < .05). CONCLUSIONS: Uncontrolled hypertension is associated with increased coronary myogenic tone and vasoconstrictive response to phenylephrine that persists after cardioplegia and cardiopulmonary bypass.

National Analysis of Sternal Wound Complications and Readmissions After Coronary Bypass Surgery.

BACKGROUND: Wound complications are a cause for readmission after cardiac surgery. Health insurance status has been associated with poor postoperative outcomes. We investigate the association between health insurance status and post-CABG wound dehiscence or infection along with 30-day wound-related readmission using a national database. METHODS: We queried the National Readmissions Database for the year 2018 for patients aged 18 years or more undergoing multivessel coronary artery bypass graft surgery (CABG). Patients were subcategorized by health insurance status (private, Medicaid, Medicare, uninsured). Our primary outcomes were wound dehiscence or infection during the index admission and 30-day readmission after discharge for wound-related complications. RESULTS: In all, 131,976 patients met inclusion criteria: 32.7% private, 7.6% Medicaid, 59.3% Medicare, and 0.4% uninsured. Compared with patients having private insurance, Medicaid patients had greater odds of readmission for superficial wound dehiscence (odds ratio [OR] 2.11; 1.11-4.00; P = .022) and deep wound dehiscence (OR 2.11; 95% CI, 1.09-4.10; P = .026), as did Medicare patients (OR 2.34; 95% CI, 1.29-3.88; P = .004; and OR 3.23; 95% CI, 1.76-5.90; P = .001, respectively). Medicaid patients additionally had higher odds of readmission for superficial wound infection (OR 1.59; 95% CI, 1.11-4.00; P = .014). Compared with patients with private insurance, Medicaid patients had higher odds of deep wound dehiscence on index admission (OR 1.97; 95% CI, 1.02-3.83; P = .044), and Medicare patients had higher odds of superficial wound dehiscence (OR 2.55; 95% CI, 1.28-5.06; P = .001). CONCLUSIONS: Patients with Medicaid and Medicare had greater odds of readmission for wound complications and higher rates of wound dehiscence in their index admission. Further research is warranted to characterize factors driving readmission due to postsurgical wound complications in low socioeconomic status populations.

Risk Factors for Heart Failure Readmission After Cardiac Surgery.

Background: Heart failure (HF) is a leading cause of readmission after cardiac surgery, yet risk factors for HF readmission after cardiac surgery remain poorly characterized. Objectives: This study aimed to identify risk factors associated with 30-day HF-specific readmissions after cardiac surgery using a national database. Methods: We queried the 2016 to 2018 National Readmissions Database to identify U.S. patients who underwent coronary artery bypass grafting (CABG), mitral valve repair/replacement, and/or aortic valve repair/replacement. Exclusion criteria included history of ventricular assist device or heart transplant, dialysis-dependent renal insufficiency, and death during index admission. Clinical variables were defined using International Classification of Diseases-10th Revision codes. The primary outcome was a 30-day readmission for HF following discharge. Multivariable logistic regression was used to account for relevant clinical and demographic covariates and identify independent risk factors for HF readmissions following cardiac surgery. Results: Our study included 394,050 patients who underwent cardiac surgery (mean age 66 ± 12 years, 63% isolated CABG, 27% isolated valve, 11% CABG + valve). Of these patients, 7,318 were readmitted within 30 days of discharge for a principal diagnosis of HF. Independent risk factors of HF-specific readmission included older age, female sex, prolonged length of stay, comorbid congestive HF, nondialysis dependent chronic kidney disease, chronic obstructive pulmonary disease, chronic liver disease, obesity, atrial fibrillation, and acute kidney injury. Prior CABG was marginally protective for HF-specific readmission. Conclusions: Using a national registry, we identified risk factors associated with HF readmission after cardiac surgery. Further analysis of these risk factors and their association with HF readmission is warranted.

Lifetime management of patients with symptomatic severe aortic stenosis: a computed tomography simulation study.

BACKGROUND: Given enough time, transcatheter heart valves (THVs) will degenerate and may require reintervention. Redo transcatheter aortic valve implantation (TAVI) is an attractive strategy but carries a risk of coronary obstruction. AIMS: We sought to predict how many TAVIs patients could undergo in their lifetime using computed tomography (CT) simulation. METHODS: We analysed paired CT scans (baseline and 30 days post-TAVI) from patients in the LRT trial and EPROMPT registry. We implanted virtual THVs on baseline CTs, comparing predicted valve-to-coronary (VTC) distances to 30-day CT VTC distances to evaluate the accuracy of CT simulation. We then simulated implantation of a second virtual THV within the first to estimate the risk of coronary obstruction due to sinus sequestration and the need for leaflet modification. RESULTS: We included 213 patients with evaluable paired CTs. There was good agreement between virtual (baseline) and actual (30 days) CT measurements. CT simulation of TAVI followed by redo TAVI predicted low coronary obstruction risk in 25.4% of patients and high risk, likely necessitating leaflet modification, in 27.7%, regardless of THV type. The remaining 46.9% could undergo redo TAVI so long as the first THV was balloon-expandable but would likely require leaflet modification if the first THV was self-expanding. CONCLUSIONS: Using cardiac CT simulation, it is possible to predict whether a patient can undergo multiple TAVI procedures in their lifetime. Those who cannot may prefer to undergo surgery first. CT simulation could provide a personalised lifetime management strategy for younger patients with symptomatic severe aortic stenosis and inform decision-making. CLINICALTRIALS: gov: NCT02628899; ClinicalTrials.gov: NCT03557242; ClinicalTrials.gov: NCT03423459.

Glycemic control is not associated with neurocognitive decline after cardiac surgery.

BACKGROUND: Whether perioperative glycemic control is associated with neurocognitive decline (NCD) after cardiac surgery was examined. METHODS: Thirty patients undergoing cardiac surgery utilizing cardiopulmonary bypass (CPB) were screened for NCD preoperatively and on postoperative day 4 (POD4). Indices of glucose control were examined. Serum cytokine levels were measured and human transcriptome analysis was performed on blood samples. Neurocognitive data are presented as a change from baseline to POD4 in a score standardized with respect to age and gender. RESULTS: A decline in neurocognitive function was identified in 73% (22/30) of patients on POD4. There was no difference in neurocognitive function between patients with elevated HbA1c levels preoperatively (p = .973) or elevated fasting blood glucose levels the morning of surgery (>126 mg/dl, p = .910), or a higher maximum blood glucose levels during CPB (>180 mg/dl, p = .252), or higher average glucose levels during CPB (>160 mg/dl, p = .639). Patients with postoperative leukocytosis (WBC ≥ 10.5) had more NCD when compared to their baseline function (p = .03). Patients with elevated IL-8 levels at 6 h postoperatively had a significant decline in NCD at POD4 (p = .04). Human transcriptome analysis demonstrated unique and differential patterns of gene expression in patients depending on the presence of DM and NCD. CONCLUSIONS: Perioperative glycemic control does not have an effect on NCD soon after cardiac surgery. The profile of gene expression was altered in patients with NCD with or without diabetes.

Increased Access to Cardiac Surgery Did Not Improve Outcomes: Early Look Into Medicaid Expansion.

BACKGROUND: Cardiac surgery utilization has increased after passage of the Affordable Care Act. This multistate study examined whether changes in access after Medicaid expansion (ME) have led to improved outcomes, overall and particularly among ethnoracial minorities. METHODS: State Inpatient Databases were used to identify nonelderly adults (ages 18-64 years) who underwent coronary artery bypass grafting, aortic valve replacement, mitral valve replacement, or mitral valve repair in 3 expansion (Kentucky, New Jersey, Maryland) vs 2 nonexpansion states (North Carolina, Florida) from 2012 to 2015. Linear and logistic interrupted time series were used with 2-way interactions and adjusted for patient-level, hospital-level, and county-level factors to compare trends and instantaneous changes at the point of ME implementation (quarter 1 of 2014) for mortality, length of stay, and elective status. Interrupted time series models estimated expansion effect, overall and by race-ethnicity. RESULTS: Analysis included 22 038 cardiac surgery patients from expansion states and 33 190 from nonexpansion states. In expansion states, no significant trend changes were observed for mortality (odds ratio, 1.01; P = .83) or length of stay (ß = -0.05, P = .20), or for elective surgery (odds ratio, 1.00; P = .91). There were similar changes seen in nonexpansion states. Among ethnoracial minorities, ME did not impact outcomes or elective status. CONCLUSIONS: Despite an increase in cardiac surgery utilization after ME, outcomes remained unchanged in the early period after implementation, overall and among ethnoracial minorities. Future research is needed to confirm long-term trends and examine reasons behind this lack of improved outcomes.

Medical malpractice in heart transplantation from 1994 to 2019.

BACKGROUND: Heart transplantation is a unique clinical intervention because it involves two separate parties, the donor and the recipient. This increases the potential for the legal liability of heart teams involved with heart transplantation, but there is no research that exists to date that analyzes the etiology of medical malpractice litigations relating to heart transplantation. METHODS: The Westlaw legal database was queried for all medical malpractice litigations concerning heart transplantation from 1994 to 2019 in the United States. Individual litigations were reviewed for inclusion, resulting in 41 included cases, and then analyzed for legal and clinical data. Statistical analyses were performed with the Fisher exact test and Mann-Whitney U tests. RESULTS: The mean age of patients involved in these litigations was 38.88 years, with female patients being younger on average. Female patients received a significantly larger average award than male counterparts (p = .03). Alleged failure to diagnose was significantly associated with settlements (p = .047). An alleged failure to obtain informed consent as presented by the plaintiff was significantly associated with defendant verdicts (p = .03). Incidence of stroke and infection were each significantly associated with nondefendant verdicts (p = .02 and p = .02). CONCLUSIONS: There should be an emphasis on documenting informed consent from all involved parties in heart transplantation to limit litigations filed against clinicians. As technologies and growing donor pools increase the prevalence of heart transplantation, clinicians would be well-served to be aware of legally tenable practices that will allow them to adopt a higher transplant volume without simultaneously adopting added legal exposure.

Cardiac Surgery Utilization Across Vulnerable Persons After Medicaid Expansion.

BACKGROUND: Medicaid expansion (ME) under the Affordable Care Act has reduced the number of uninsured patients, although its preferential effects on vulnerable populations have been mixed. This study examined whether ME preferentially improved cardiac surgery use by insurance strata, race, and income level. METHODS: Non-elderly adults (aged 18-64 years) who underwent coronary artery bypass grafting, aortic valve replacement, mitral valve replacement, or mitral valve repair were identified in the State Inpatient Databases for 3 expansion states (Kentucky, New Jersey, and Maryland) and 2 non-expansion states (North Carolina and Florida) from 2012 to the third quarter of 2015. We used adjusted Poisson interrupted time series to determine the impact of ME on cardiac surgery use for Medicaid or uninsured (MCD/UIS) patients, racial and ethnic minorities, and individuals from low-income areas. RESULTS: In expansion states, use among non-White MCD/UIS patients had a positive trend after ME (2.3%/quarter; P = .156), whereas use for White MCD/UIS patients fell (-1.7%/quarter; P = .117). In contrast, use among non-White MCD/UIS in non-expansion states decreased by 4.4% (P < .001) which was a greater decline than among White MCD/UIS patients (-1.8%/quarter; P = .057). There was no substantial effect of ME on cardiac surgery use for MCD/UIS patients from low- versus high-income areas. CONCLUSIONS: These findings demonstrate that the use of cardiac surgical procedures was generally unchanged after ME; however, nonsignificant trend differences suggest a narrowing gap between vulnerable and non-vulnerable groups in ME states. These preliminary findings help describe the association of insurance coverage as a driver of cardiac surgery use among vulnerable patients.

Institutional Red Blood Cell Transfusion Rates Are Correlated Following Endovascular and Surgical Cardiovascular Procedures: Evidence That Local Culture Influences Transfusion Decisions.

Background The relationship between local hospital culture and transfusion rates following endovascular and surgical cardiovascular procedures has not been well studied. Methods and Results Patients undergoing coronary revascularization, aortic valve replacement, lower extremity peripheral vascular intervention, or carotid artery revascularization from up to 852 US hospitals in the Nationwide Readmissions Database were identified. Crude and risk-standardized red blood cell transfusion rates were determined for each procedure. Pearson correlation coefficients were calculated between respective procedural transfusion rates. Median odds ratios were estimated to reflect between-hospital variability in red blood cell transfusion rates following the same procedure for a given patient. There was wide variation in red blood cell transfusion rates across different procedures, from 2% following carotid endarterectomy to 29% following surgical aortic valve replacement. For surgical and endovascular modalities, transfusion rates at the same hospital were highly correlated for aortic valve replacement (r=0.67; P<0.001), moderately correlated for coronary revascularization (r=0.56; P<0.001) and peripheral vascular intervention (r=0.51; P<0.001), and weakly correlated for carotid artery revascularization (r=0.19, P<0.001). Median odds ratios were all >2, highest for coronary artery bypass graft surgery and surgical aortic valve replacement, indicating substantial site variation in transfusion rates. Conclusions After adjustment for patient-related factors, wide variation in red blood cell transfusion rates remained across surgical and endovascular procedures employed for the same cardiovascular condition. Transfusion rates following these procedures are highly correlated at individual hospitals and vary widely across hospitals. In aggregate, these findings suggest that local institutional culture significantly influences the decision to transfuse following invasive cardiovascular procedures and highlight the need for randomized data to inform such decisions.

Effects of neuropeptide Y on the microvasculature of human skeletal muscle.

BACKGROUND: Neuropeptide Y acts directly on the vasculature as a cotransmitter with norepinephrine for an augmented contraction. Little, however, is known about the effects of neuropeptide Y on the microvasculature of human skeletal muscle. Neuropeptide Y signaling has not been studied in the setting of cardiac surgery and cardiopulmonary bypass. We investigated the role of neuropeptide Y signaling on vasomotor tone in the microvessels of human skeletal muscle, as well as the effect of cardiopulmonary bypass on neuropeptide Y-induced responsiveness. METHODS: Specimens taken from intercostal muscles were collected from patients, pre- and post-cardiopulmonary bypass, undergoing coronary artery bypass grafting or cardiac valve surgery (n = 8/group). Microvessels (157 ± 47 microns) were isolated in vitro in a no-flow state. Arterial microvascular responses to a neuropeptide Y agonist, a Y1 receptor antagonist, phenylephrine, and the coadministration of neuropeptide Y and phenylephrine were examined. The abundance and localization of the Y1 receptor were measured using Western blot and immunofluorescence, respectively. RESULTS: Arterial microvessels showed responsiveness to the neuropeptide Y agonist (10-9 to 4 × 10-7 mol/L) both before and after cardiopulmonary bypass, reaching a 12.5% vasoconstriction from the baseline luminal diameter. With administration of the Y1 receptor antagonist after neuropeptide Y, the contractile response was eliminated (n = 3/group, P = .04). No difference in vasoconstriction was observed between pre- and post-cardiopulmonary bypass groups (P = .73). The coadministration of neuropeptide Y and phenylephrine (10-9 to 10-4 mol/L) elicited no difference in vasoconstriction (n = 7/group, P = .06 both pre- and post-cardiopulmonary bypass) when compared with phenylephrine alone (10-9 to 10-4 mol/L). No change in the protein expression or localization of the Y1 receptor was detected by Western blotting (n = 6/group, P = .44) or immunofluorescence (n = 6/group, P = .13). CONCLUSION: Neuropeptide Y induced vasoconstriction, suggesting that neuropeptide Y may play an important role in the regulation of the peripheral microvasculature. There was no change in microvascular responsiveness to neuropeptide Y after cardiopulmonary bypass nor were there any synergistic effects of neuropeptide Y on phenylephrine-induced vasoconstriction in the skeletal muscle microvasculature.

Impact of Transcatheter Aortic Valve Replacement on Risk Profiles of Surgical Aortic Valve Replacement Patients.

BACKGROUND: The advent of transcatheter aortic valve replacement (TAVR) has changed which patients undergo surgical aortic valve replacement (SAVR). We sought to understand the impact of TAVR on the characteristics of SAVR patients in the United States. METHODS: A cohort of 2959 patients who underwent isolated SAVR at 11 US hospitals that perform both TAVR and SAVR from 2013 through 2017 were grouped by the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database version (v)2.73 (2011-2014), v2.81 (2014-2017), and v2.9 (2017) to assess temporal trends in patient characteristics. RESULTS: Over time, SAVR patients were younger with fewer preoperative comorbidities. There was a significant decrease in median STS predicted risk of mortality (PROM) score (2.0 vs. 1.8 vs. 1.3, p < 0.001, in v2.73 vs. v2.81 vs. v2.9). Specifically, there were fewer high-risk (STS PROM > 8%: 4.3% vs. 4.7% vs. 1.2%, p = 0.03) and intermediate-risk (STS PROM 4% to 8%: 16.3% vs. 11.7% vs. 4.3%, p < 0.001) patients. The proportion of patients with bicuspid aortic valve disease increased significantly (11.2% vs. 26.9% vs. 36.6%, p < 0.001). There were no differences in operative mortality (1.9% vs. 2.1% vs. 1.4%, p = 0.75). CONCLUSIONS: The introduction of TAVR has already impacted the demographics, clinical characteristics and risk profiles of patients undergoing SAVR in the US. Now that TAVR is approved for low-risk patients, SAVR is likely to be reserved for younger patients who are willing to receive a mechanical valve and for patients with aortopathy, coronary artery disease, or concomitant mitral or tricuspid pathology.

Seasonality of postoperative pneumonia after coronary artery bypass grafting: A national inpatient sample study.

BACKGROUND: The development of postoperative pneumonia following cardiac surgery is associated with significant morbidity and mortality. However, seasonal variation as a risk factor for the development of postoperative pneumonia remains to be investigated. We sought to investigate whether patients undergoing coronary artery bypass grafting (CABG) during "flu season" (Fall and Winter months) at increased risk of postoperative pneumonia. MATERIALS AND METHODS: A retrospective cohort study of patients undergoing CABG in the National Inpatient Sample between 2005 and 2015 was completed. Concomitant diagnosis of pneumonia was defined as the primary outcome. Secondary outcomes were defined to include pneumonia secondary to several known pathogens. Outcomes with significant differences between Fall/Winter and Spring/Summer groups were further analyzed with additive time series decomposition. Odds ratios were generated and adjusted for age, sex, elective status, and 29 other Agency for Healthcare Research and Quality comorbidity measures. RESULTS: A total of 238 757 and 277 941 patients undergoing CABG during Fall/Winter and Spring/Summer, respectively, were identified. A significantly increased risk of postoperative pneumonia (adjusted odds ratio [aOR] = 1.15) and infection with influenza (aOR = 4.08), Haemophilus influenzae (aOR = 1.40), and Streptococcus pneumoniae (aOR = 1.47) was observed among patients receiving CABG in Q1 (January-March) compared to Q3 (July-September). CONCLUSIONS: There is a strong seasonality in the incidence of postoperative pneumonia after CABG which may persist across other cardiothoracic surgeries. In addition to optimizing infection control and perioperative care, cardiac surgeons should consider preoperative vaccination against seasonal influenza, H. influenzae, and S. pneumoniae to improve outcomes among high-risk patients.