K. Shahzad

Pre-operative and post-operative risk factors associated with neurologic complications in patients with advanced heart failure supported by a left ventricular assist device

BACKGROUND Neurologic complications (NCs) are the major adverse events after left ventricular assist device (LVAD) surgery. Pre-operative and post-operative factors associated with NCs in patients with LVADs were investigated. METHODS We reviewed 307 consecutive patients undergoing LVAD surgery (167 HeartMate I and 140 HeartMate II devices) at Columbia University Medical Center between November 2000 and December 2010. Clinical characteristics and hemodynamic and laboratory indexes were analyzed. NC was defined according to the Interagency Registry for Mechanically Assisted Circulatory Support definition of neurologic dysfunction, including transient ischemic attack (TIA) and ischemic or hemorrhagic cerebrovascular accident (CVA). RESULTS NCs developed in 43 patients (14.0%) at 91.8 ± 116.3 days post-operatively. The frequency of NC development was similar in HeartMate I and II patients. Patients with NC showed a higher frequency of pre-LVAD CVA history (27.9% vs 15.5%, p = 0.046), lower pre-operative sodium (129.0 ± 7.0 vs 132.1 ± 8.1 mg/dl, p = 0.018) and albumin concentrations (3.5 ± 0.7 vs 3.7 ± 0.6 mg/dl, p = 0.049), lower post-operative hematocrit (34.9% ± 5.1% vs 37.8% ± 6.1%, p = 0.0034), sodium (131.6 ± 7.7 vs 134.4 ± 6.4 mg/dl, p = 0.010) and albumin concentrations (3.7 ± 0.5 vs 3.9 ± 0.5 mg/dl, p = 0.0016), and higher frequency of post-operative infection (39.5% vs 19.3%, p = 0.003) than those without NC. Multiple regression analysis revealed that CVA history (odds ratio, 2.37, 95% confidence interval, 1.24-5.29; p = 0.011) and post-operative infection (odds ratio, 2.99, 95% confidence interval, 1.16-10.49; p = 0.011) were highly associated with NC development. The combination of CVA history, pre-operative and post-operative sodium and albumin, and post-operative hematocrit and infection could discriminate patients developing NCs with a probability of 76.6%. CONCLUSIONS Previous stroke, persistent malnutrition and inflammation, severity of heart failure, and post-LVAD infections are key factors associated with development of NCs after LVAD implantation.

Hepatic dysfunction and survival after orthotopic heart transplantation: Application of the MELD scoring system for outcome prediction

BACKGROUND The prevalence of heart failure (HF) is rising and the only corrective treatment is cardiac transplantation. Advanced HF is associated with congestive hepatopathy and progressive functional and ultrastructural changes of the liver. We hypothesized that hepatic dysfunction is associated with impaired clinical outcome after heart transplantation. METHODS Data of 617 adult patients (75% men, mean age 53 ± 12 years, mean BMI 25 ± 4, mean ejection fraction 19 ± 9%) undergoing orthotopic heart transplantation (OHT) were analyzed retrospectively. Deviation from institutional normal ranges was used to define abnormal liver function. Standard Model for End-stage Liver Disease (MELD) scores were calculated and a modified MELD score with albumin replacing INR (modMELD) was created to eliminate the confounding effects of anti-coagulation. RESULTS Before OHT, AST, ALT and total bilirubin were elevated in 20%, 18% and 29% of the population, respectively. Total protein and albumin were decreased in 25% and 52% of the population, respectively. By 2 months post-transplantation, percentages of individuals with pathologic values decreased significantly, except for ALT, total protein and albumin, all of which took longer to normalize. Individuals with a higher pre-transplantation MELD or modMELD score had worse outcome 30 days post-transplant and reduced long-term survival over a 10-year follow-up. CONCLUSIONS In this large, single-center retrospective study, we demonstrated the dynamics of liver dysfunction after cardiac transplantation and that elevated MELD scores indicating impaired liver function are associated with poor clinical outcome after OHT. Thus, pre-operative liver dysfunction has a significant impact on survival of patients after cardiac transplantation.

Dynamics in Insulin Resistance and Plasma Levels of Adipokines in Patients With Acute Decompensated and Chronic Stable Heart Failure

BACKGROUND Patients with heart failure (HF) develop metabolic derangements including increased adipokine levels, insulin resistance, inflammation and progressive catabolism. It is not known whether metabolic dysfunction and adipocyte activation worsen in the setting of acute clinical decompensation, or conversely, improve with clinical recovery. METHODS AND RESULTS We assessed insulin resistance using homeostasis model assessment of insulin resistance (HOMA-IR), and measured plasma levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP), adiponectin, visfatin, resistin, leptin, and tumor necrosis factor (TNF) α in 44 patients with acute decompensated HF (ADHF) due to left ventricular (LV) systolic dysfunction and again early (<1 wk) and late (> 6 mo) after clinical recovery, in 26 patients with chronic stable HF, and in 21 patients without HF. NT-proBNP was not increased in control subjects, mildly elevated in patients with stable HF, markedly elevated in patients with ADHF, and decreased progressively early and late after treatment. Compared to control subjects, plasma adiponectin, visfatin, leptin, resistin, and TNF-α were elevated in patients with chronic stable HF and increased further in patients with ADHF. Likewise, HOMA-IR was increased in chronic stable HF and increased further during ADHF. Adiponectin, visfatin, and HOMA-IR remained elevated at the time of discharge from the hospital, but returned to chronic stable HF levels. Adipokine levels were not related to body mass index in HF patients. HOMA-IR correlated positively with adipokines and TNF-α in HF patients. CONCLUSIONS ADHF is associated with worsening of insulin resistance and elevations of adipokines and TNF-α, indicative of adipocyte activation. These metabolic abnormalities are reversible, but they temporally lag behind the clinical resolution of decompensated HF.