Endothelial Damage and Muscle Wasting in Cardiac Surgery Patients

This is a post-hoc analysis to assess the effect of anesthesia, surgical trauma, and extracorporeal circuit on endothelial integrity, microvascular permeability, and extracellular fluid balance, as well as on skeletal muscle catabolism, in patients undergoing elective cardiac surgery. We included 127 well-nourished patients undergoing “on-pump” elective cardiac surgery. One day prior to surgery (D0) and again on postoperative day 7 (POD7), body mass index, body composition assessment, hand-grip strength (HGS), and mid-upper arm muscle circumference (MAMC) were measured. Patients were assigned to early recovery (ER) and late recovery (LR) groups, depending on the duration of ICU stay (cut-off 48 hours). The magnitude of change (Δ) in all parameters studied was assessed in ER versus LR groups, regarding (i) epithelial tissue dysfunction (Δ-Extra-Cellular Water percentage (Δ-ECW%), Δ-Phase Angle (Δ-PhA)), (ii) skeletal muscle mass catabolism (Δ-Skeletal muscle mass reduction%, Δ-Hand Grip Strength (Δ-HGS) and Δ-Mid Upper-Arm Muscle Circumference (Δ-MAMC)). Baseline measurements were similar in both groups. A significant difference was observed in all Δ-parameters studied (Δ-ECW%, Δ-PhA and muscle catabolism, Δ-HGS, Δ-MAMC), the worse results being correlated to the LR group. The results raise the issue that patients with early recovery may silently have pathological conditions, continuing even on the day of discharge - further research should be planned.

Role of nutritional indices in predicting outcomes of vascular surgery

BACKGROUND

Malnutrition is frequent among vascular surgery patients, given their age, chronic comorbidities, and poor functional status, and it is believed to increase their operative risk. We aimed to assess the combined use of recent significant weight loss (>10% body mass) and serum albumin levels as a nutritional status index to predict outcomes.

METHODS

We analyzed vascular surgery data from the American College of Surgeons National Surgical Quality Improvement Program database (2005-2012; N = 238,082) to compare operative death (in-hospital and 30-day operative death) across eight nutritional status groups based on weight loss (yes/no) and albumin category: very low albumin level (VL-Alb; <2.50 g/dL), low albumin level (L-Alb; 2.50-3.39 g/dL), normal albumin level (N-Alb; 3.40-4.39 g/dL), and high albumin level (H-Alb; 4.40-5.40 g/dL). Risk-adjusted odds ratios (AOR) with 95% confidence intervals were estimated by multivariable logistic regression (N-Alb [no weight loss], reference).

RESULTS

The study population included 113,936 patients for whom albumin level was available (age, 67 ± 13 years; 60.2% male). Operative death was documented in 5160 (4.53%) patients. The eight-category nutritional status was more predictive of operative death than age alone (C statistic, 0.74 vs 0.63). A high discrimination multivariable model for operative death was derived (C statistic, 0.851). Low albumin level was associated with increased death that worsened in case of weight loss: VL-Alb + WL, AOR = 3.83 (3.03-4.83); VL-Alb, AOR = 3.36 (3.06-3.69); L-Alb + WL, AOR = 2.46 (1.98-3.05); and L-Alb, AOR = 1.99 (1.84-2.15). Weight loss was associated with increased death even if albumin level was normal: N-Alb + WL, AOR = 1.77 (1.34-2.35); and H-Alb + WL, AOR = 1.91 (0.69-5.31). H-Alb was protective (AOR = 0.65 [0.55-0.76]).

CONCLUSIONS

Nutritional status predicts outcomes of vascular surgery. Serum albumin level and weight loss should be incorporated in patients' risk stratification.

Prognostic Implications of Changes in Albumin Following Left Ventricular Assist Device Implantation in Patients With Severe Heart Failure

Mechanical assist devices have emerged as an established therapeutic option for patients with end-stage heart failure. Because preimplant hypoalbuminemia is a known risk factor for adverse outcomes, we hypothesized that change in albumin may be a prognostic indicator in patients with continuous-flow left ventricular assist devices (cfLVADs). This is a retrospective single-center study of patients who underwent cfLVAD implantation (HeartMate II and HeartWare HVAD) at an academic center from 2008 to 2014. After excluding those who died, were transplanted, or hospitalized during the first 3 months post-implant, albumin values were obtained and stratified by an increase or a decrease from pre-implant to 3 months post-implant on 171 (81% male, mean age 57 ± 16 years) patients (139 for the survival analysis and 90 for the hospitalization analysis). Decrease in albumin from pre-implant to 3 months after implant correlated with increased mortality (hazard ratio 2.93, confidence interval 1.57 to 5.44, p <0.01) and reduced time to next hospitalization (hazard ratio 1.70, confidence interval 1.03 to 2.81, p = 0.04). The Kaplan-Meier survival curve estimated a 49.43% 2-year survival rate in those whose albumin decreased versus 83.62% in those whose albumin increased over 3 months (p <0.01). Improved outcomes were seen in patients whose albumin normalized versus patients whose albumin remained normal over 3 months. In conclusion, our study is the first to demonstrate the importance of change in albumin from pre- to postimplant on the prognosis of cfLVAD patients. Future studies are needed to determine whether therapeutic intervention to improve albumin post-implant will prevent hospitalizations and improve outcomes.

Poor preoperative nutritional status is an important predictor of the retardation of rehabilitation after cardiac surgery in elderly cardiac patients

BACKGROUND

Preoperative nutritional status and physical function are important predictors of mortality and morbidity after cardiac surgery. However, the influence of nutritional status before cardiac surgery on physical function and the progress of postoperative rehabilitation requires clarification.

AIMS

To determine the effect of preoperative nutritional status on preoperative physical function and progress of rehabilitation after elective cardiac surgery.

METHODS

We enrolled 131 elderly patients with mean age of 73.7 ± 5.8 years undergoing cardiac surgery. We divided them into two groups by nutritional status as measured by the Geriatric Nutritional Risk Index (GNRI): high GNRI group (GNRI ≥ 92, n = 106) and low GNRI group (GNRI < 92, n = 25). Physical function was estimated by handgrip strength, knee extensor muscle strength (KEMS), the Short Physical Performance Battery (SPPB), and 6-minute walk test (6MWT). Progress of postoperative rehabilitation was evaluated by the number of days to independent walking after surgery, length of stay in the ICU, and length of hospital stay.

RESULTS

After adjusting for potential confounding factors, preoperative handgrip strength (P = 0.034), KEMS (P = 0.009), SPPB (P < 0.0001), and 6MWT (P = 0.012) were all significantly better in the high GNRI group. Multiple regression analysis revealed that a low GNRI was an independent predictor of the retardation of postoperative rehabilitation.

CONCLUSIONS

Preoperative nutritional status as assessed by the GNRI could reflect perioperative physical function. Preoperative poor nutritional status may be an independent predictor of the retardation of postoperative rehabilitation in patients undergoing elective cardiac surgery.

Development of an Integrated Theory of Surgical Recovery in Older Adults

Experts argue the health care system is not prepared to meet the unique needs of older surgical patients, including how to provide the best care during the recovery phase. Nutrition plays a critical role in the recovery of surgical patients. Since older adults are at risk for malnutrition, examining the role of nutrition as a mediator for surgical recovery across the care continuum in older adults is critical. Presently there is a paucity of frameworks, models, and guidelines that integrate the role of nutrition on the trajectory of postoperative recovery in older surgical patients. The purpose of this article is to introduce the Integrated Theory of Surgical Recovery in Older Adults, an interdisciplinary middle-range theory, so that scholars, researchers, and clinicians can use this framework to promote recovery from surgery in older adults by considering the contribution of mediators of recovery (nutritional status, functional status, and frailty) unique to the older adults.

Influence of undernutrition at admission on clinical outcomes in patients with acute myocardial infarction

BACKGROUND

Although the effect of overweight or obesity on clinical outcomes in patients with acute myocardial infarction (MI) has been reported, the effect of undernutrition is not as well understood. Therefore, we investigated whether acute MI patients frequently present with undernutrition, and whether this influences poor clinical outcomes.

METHODS AND RESULTS

Using the Korea Acute Myocardial Infarction Registry database, we screened initial data on acute MI patients admitted within 48h of symptom onset to a tertiary university hospital between November 1, 2011 and May 31, 2015. We then assessed nutritional status at admission, using the Geriatric Nutritional Risk Index (GNRI). Of a total of 2251 patients, there were 1585 (70.4%) men, and mean age was 65.0±12.8 years. Based on GNRI score, undernutrition at admission was present in 409 (18.2%) patients. Multiple logistic regression analysis found undernutrition to be an independent factor influencing post-MI complications [odds ratio (OR), 2.13; 95% confidence interval (CI), 1.61-2.84; p<0.001], after adjusting for age, sex, hypertension, diabetes, hyperlipidemia, previous stroke, smoking, diagnosis, number of involved vessel lesions, Killip class, atrial fibrillation, baseline blood pressure, hemoglobin, creatine kinase-MB, creatinine, performance of percutaneous coronary intervention, reperfusion time, recanalization, and use of antithrombotics. Undernutrition was also an important factor influencing in-hospital death (OR, 2.48; 95% CI, 1.55-3.95; p<0.001), after adjusting for all potential factors by univariate analysis.

CONCLUSIONS

Nutritional status is a significant prognostic factor in clinical outcomes after MI during hospitalization. Therefore, nutritional assessment and intervention, especially for undernourished MI patients, should be considered.

Modifying a generic postoperative recovery profile instrument to an instrument specifically targeting coronary artery bypass grafting

Patients may suffer from a wide range of postoperative symptoms after coronary artery bypass grafting. In-depth knowledge of the recovery process is a prerequisite for nursing interventions. However, we found no specific instrument covering the entire range and duration of postoperative symptoms related to this procedure. We therefore modified and extended the 19 items, generic Postoperative Recovery Profile questionnaire for the specific evaluation of the recovery after coronary artery bypass grafting. We here report on the development process of the new questionnaire. Procedure-specific symptoms were identified by a literature review and by experts. The content validity was assessed by healthcare professionals (n = 15), inpatients (n = 12) and outpatients (n = 4). A test run was done with inpatients (n = 10), which was followed by a test-retest reliability evaluation with inpatients (n = 24). We identified 15 new symptoms in the literature review and six in the content validity assessment. Only three of the 35 items had an acceptable content validity index, but all 35 items in the test run were reported by at least two patients. The questionnaire took 4-9 minutes to complete and was considered easy to use. The final instrument used in the reliability test included 22 new items, and 25 of the 35 items were satisfactory stable. To conclude, we developed a 35 items, procedure-specific questionnaire that was easy to use and may aid systematic assessment of the recovery after coronary artery bypass grafting.

Relation of preoperative serum albumin levels to survival in patients undergoing left ventricular assist device implantation

Hypoalbuminemia has been recognized as a prognostic indicator in patients with heart failure. We aimed to investigate the association of hypoalbuminemia with postoperative mortality in patients undergoing left ventricular assist device (LVAD) implantation. We studied 272 consecutive patients undergoing LVAD implantation from 2000 to 2010 at our institution. Preoperative clinical characteristics and laboratory variables associated with mortality were analyzed. Postoperative survival of patients with preoperative hypoalbuminemia (<3.5 g/dl, n = 125) and those with normal albumin concentration (≥3.5 g/dl, n = 147) was compared. Survival after LVAD surgery was better in patients with normal albumin levels compared with those with hypoalbuminemia before surgery (3 and 12 months: 93.2% vs 82.4% and 88.4% vs 75.2%, respectively, p <0.001). Multivariate analysis revealed that preoperative albumin was independently associated with mortality after LVAD implantation (hazard ratio 0.521, 95% confidence interval 0.290 to 0.934; p = 0.029.) Furthermore, the impact of normalization of albumin levels during LVAD support on postoperative survival was analyzed in both groups. Subgroup analysis of patients with preoperative hypoalbuminemia and postoperative normalization of albumin levels (n = 81) showed improved survival compared with those who remained hypoalbuminemia (n = 44) or those who had decreasing albumin levels during LVAD support (n = 40; 3-month survival: 92.6% vs 63.6% and 65.0%; p <0.01). In conclusion, preoperative hypoalbuminemia is associated with poor prognosis after LVAD surgery. Postoperative normalization of albumin level is associated with improved survival. Attention to albumin levels by correcting nutrition, inflammation, and hepatic function could be an effective way to improve prognosis in patients evaluated for LVAD implantation.

Inflammation, Functional Status, and Weight Loss During Recovery From Cardiac Surgery in Older Adults

Objective:

To determine the nutritional, inflammatory, and functional aspects of unintentional weight loss after cardiac surgery that warrant further investigation.

Research Methods and Procedures:

Twenty community-dwelling adults > 65 years old undergoing cardiac surgery (coronary artery bypass graft [CABG] or CABG + valve) were recruited for this prospective longitudinal (preoperative and 4–6 weeks postdischarge) pilot study. Anthropometrics (weight, standing height, and mid-arm and calf circumference), nutritional status (Mini-Nutritional Assessment™ [MNA]), appetite, physical performance (timed chair stand), muscle strength (hand grip) and functional status (basic and instrumental activities of daily living), and inflammatory markers (plasma leptin, ghrelin, interleukin [IL]-6, high-sensitivity[hs] C-reactive protein, and serum albumin and prealbumin) were measured.

Results:

Participants who completed the study ( n = 11 males, n = 3 females) had a mean age 70.21 ± 4.02 years. Of these, 12 lost 3.66 ± 1.44 kg over the study period. Weight, BMI, activities of daily living, and leptin decreased over time ( p < .05). IL-6 increased over time ( p < .05). Ghrelin, hs-CRP, and timed chair stand increased over time in those who underwent combined procedures ( p < .05). Grip strength decreased in those who developed complications ( p = .004). Complications, readmission status, and lowered grip strength were found in those with low preoperative MNA scores ( p < .05).

Conclusion:

After cardiac surgery, postdischarge weight loss occurs during a continued inflammatory response accompanied by decreased physical functioning and may not be a positive outcome. The impacts of weight loss, functional impairment, and inflammation during recovery on disability and frailty warrant further study.

Preoperative serum albumin levels predict 1-year postoperative survival of patients undergoing heart transplantation

BACKGROUND

Serum albumin concentration has been recognized as a marker of nutrition, severity of inflammation, and hepatic function in patients with various chronic diseases. The purpose of this study was to investigate the impact of pretransplant serum albumin concentration on post-transplant outcome in heart transplant recipients.

METHODS AND RESULTS

Preoperative laboratory variables, including albumin concentration and donor-related information, were obtained from 822 consecutive patients undergoing heart transplant at Columbia University Medical Center between 1999 and 2010. The association between pretransplant albumin concentration and post-transplant 1-year survival was analyzed. Available data from the United Network for Organ Sharing (n=13671) were also analyzed to evaluate the impact of preoperative albumin levels on post-transplant outcome. In our cohort, multivariable analysis revealed that preoperative albumin (mg/dL; hazard ratio, 0.46; P<0.0001) and preoperative total bilirubin (mg/dL; hazard ratio, 1.26; P=0.0002) were associated with post-transplant 1-year mortality. This implied that for every 1 mg/dL increase in albumin concentration, the post-transplant 1-year mortality rate decreased by 54%. The Kaplan-Meier analysis based on our patients cohort and the United Network for Organ Sharing dataset showed lower survival rate at 1-year post-transplant in patients with albumin levels ≤ 3.5 mg/dL compared with those with >3.5 mg/dL (our patients, 91.3 versus 72.4%; P<0.0001; United Network for Organ Sharing, 88.4 versus 84.8%; P<0.0001).

CONCLUSIONS

Pretransplant serum albumin concentration is a strong prognostic marker for post-transplant survival in heart transplant recipients.

Hypoalbuminemia and long-term survival after coronary artery bypass: a propensity score analysis

BACKGROUND

Hypoalbuminemia is associated with increased morbidity in surgical patients. The impact of low albumin level on survival in cardiac surgical patients is unknown. We hypothesized that a low preoperative albumin level negatively affects long-term survival after coronary artery bypass graft (CABG) surgery.

METHODS

We reviewed prospectively gathered data from the records of 1,164 consecutive patients who underwent primary isolated CABG at our institution between 1997 and 2007. Propensity score analysis of 18 preoperative and intraoperative variables balanced potential confounding factors between the two groups of patients, so that the final study cohort consisted of 588 patients: 294 with a preoperative albumin level less than 3.5 g/dL (ie, hypoalbuminemia) and 294 patients with a preoperative albumin level of 3.5 g/dL or greater. We assessed long-term survival by using Kaplan-Meier curves generated by log rank tests.

RESULTS

The two groups of patients were well matched in terms of preoperative and intraoperative covariates. Both groups had similar early outcomes, including 30-day mortality rates (2.0% versus 1.7%; p = 0. 76) and the incidence of major adverse cardiac events (2.7% versus 2.7%; p = 1.0). However, patients with hypoalbuminemia had a significantly worse 8-year survival rate (65% ± 7% versus 86% ± 3%; hazard ratio 2.2; 95% confidence interval: 1.4 to 3.6; p = 0.001) than patients without hypoalbuminemia.

CONCLUSIONS

Although preoperative hypoalbuminemia did not predict increased early postoperative mortality or morbidity in CABG patients, it did independently predict poor long-term survival after CABG. Identifying the mechanism that underlies this relationship is essential in improving overall survival among patients with low serum albumin levels who are undergoing surgical myocardial revascularization.

Endovascular aneurysm repair is associated with less malnutrition than open abdominal aortic aneurysm repair

BACKGROUND

Patients undergoing abdominal aortic aneurysm (AAA) repair have high rates of postoperative malnutrition. We examined whether endovascular aneurysm repair (EVAR) is associated with reduced postoperative malnutrition compared with open AAA repair.

METHODS

The records of patients undergoing AAA repair in the Veterans Affairs (VA) Connecticut Healthcare System were reviewed. Primary outcomes were 30-day morbidity, lengths of hospitalization and intensive care unit stay, duration of intubation, and nutritional risk index scores.

RESULTS

Sixty-two patients were included (open repair, 37; EVAR, 25). Nutritional parameters were comparable between groups before surgery. Patients treated with EVAR had improved postoperative nutritional profiles as determined by albumin level (3.7 +/- .08 vs 3.2 +/- .12; P = .003), and nutritional risk index (97.9 +/- 1.3 vs 88.9 +/- 1.8; P = .0006), compared with patients treated with open repair.

CONCLUSIONS

Patients undergoing EVAR developed significantly less postoperative malnutrition compared with those having open repair. EVAR may be a strategy to avoid malnutrition and improve outcomes in patients at risk for malnutrition after undergoing AAA repair.