Guillermo Reyes

Bloodless Cardiac Surgery in Jehovah's Witnesses: Outcomes Compared With a Control Group

INTRODUCTION AND OBJECTIVES Some patients, such as Jehovahs Witnesses, refuse to use blood products, which can make it difficult to achieve the same outcomes as in the general population. The objective of this study was to determine whether clinical characteristics and surgical outcomes in Jehovahs Witnesses undergoing cardiac surgery are similar to those in other patients. METHODS Paired-group retrospective cohort study. All Jehovahs Witnesses undergoing cardiac surgery between January 1998 and September 2006 were included (n=59). Cases were matched on a 1:1 basis according to sex, age (5) years, year and type of surgery, and need for repeat surgery. Preoperative, intraoperative and postoperative data were analyzed. RESULTS The mean age of cases was 62.5 (11.1) years with 57.6% being female. Some 30.5% had had at least one previous cardiac intervention. The clinical characteristics of the two groups were similar. Hemoglobin and hematocrit levels were higher in Jehovahs Witnesses both before (13.6 g/dL vs 12.9 g/dL; P=.01, and 40.7% vs 39%; P=.09) and after (11 g/dL vs 10 g/dL; P=.003, and 34.2% vs 30.7%; P=.001) surgery. Jehovahs Witnesses experienced significantly less bleeding, were intubated for fewer hours, and had shorter stays in both intensive care and the hospital. There was no difference in the rate of postoperative complications or mortality. CONCLUSIONS The clinical characteristics of Jehovahs Witnesses were similar to those of the control group. The complication rate was also similar in these patients, though the number of hours of mechanical ventilation was less, 24-hour bleeding was less, and the hospital stay was shorter. Mortality was similar in the two groups.

Wearable defibrillator use in heart failure (WIF): results of a prospective registry

BackgroundHeart failure (HF) patients have a high risk of death, and implantable cardioverter defibrillators (ICDs) are effective in preventing sudden cardiac death (SCD). However, a certain percentage of patients may not be immediate candidates for ICDs, particularly those having a short duration of risk or an uncertain amount of risk. This includes the newly diagnosed patients, as well as those on the cardiac transplant list or NYHA class IV heart failure patients who do not already have an ICD. In these patients, a wearable cardioverter defibrillator (WCD) may be used until long term risk of SCD is defined. The purpose of this study was to determine the incidence of SCD in this population, and the efficacy of early defibrillation by a WCD.MethodsTen enrolling centers identified 89 eligible HF patients who were either listed for cardiac transplantation, diagnosed with dilated cardiomyopathy, or receiving inotropic medications. Data collected included medical history, device records, and outcomes (including 90 day mortality).ResultsOut of 89 patients, final data on 82 patients has been collected. Patients wore the device for 75±58 days. Mean age was 56.8±13.2, and 72% were male. Most patients (98.8%) were diagnosed with dilated cardiomyopathy with a low ejection fraction (<40%) and twelve were listed for cardiac transplantation. Four patients were on inotropes. There were no sudden cardiac arrests or deaths during the study. Interestingly, 41.5% of patients were much improved after WCD use, while 34.1% went on to receive an ICD.ConclusionsIn conclusion, the WCD monitored HF patients until further assessment of risk. The leading reasons for end of WCD use were improvement in left ventricular ejection fraction (LVEF) or ICD implantation if there was no significant improvement in LVEF.

Mid term results after bone marrow laser revascularization for treating refractory angina

BackgroundTo evaluate the midterm results of patients with angina and diffuse coronary artery disease treated with transmyocardial revascularization in combination with autologous stem cell therapy.MethodsNineteen patients with diffuse coronary artery disease and medically refractory class III/IV angina were evaluated between June 2007 and December 2009 for sole therapy TMR combined with intramyocardial injection of concentrated stem cells. At the time of surgery, autologous bone marrow (120cc) was aspirated from the iliac crest. A cardiac MRI and an isotopic test were performed before and after the procedure. Follow-up was performed by personal interview.ResultsThere were no perioperative adverse events including no arrhythmias. Mean number of laser channels was 20 and the mean total number of intramyocardially injected cells per milliliter were: total mononuclear cells(83.6 × 106), CD34+ cells(0.6 × 106), and CD133+ cells(0.34 × 106). At 12 months mean follow-up average angina class was significantly improved (3.4 ± 0.5 vs 1.4 ± 0.6; p = 0.004). In addition, monthly cardiovascular medication usage was significantly decreased (348 ± 118 vs. 201 ± 92; p = 0.001). At six months follow up there was a reduction in the number of cardiac hospital readmissions (2.9 ± 2.3 vs. 0.5 ± 0.8; p < 0.001). MRI showed no alterations regarding LV volumes and a 3% improvement regarding ejection fraction.ConclusionsThe stem cell isolator efficiently concentrated autologous bone marrow derived stem cells while the TMR/stem cell combination delivery device worked uneventfully. An improvement in clinical status was noticed in the midterm follow-up. Images test showed no morphological alterations in the left ventricle after the procedure.

Cell saving systems do not reduce the need of transfusion in low-risk patients undergoing cardiac surgery.

OBJECTIVES Cell saving systems have been widely used to reduce blood loss and need of transfusions. These device are mainly indicated in complex cardiac surgery procedures and in those patients with a high risk of bleeding. However, it is not clear if there is a benefit of a cell saver (CS) system in low-risk patients undergoing cardiac surgery. Our aim was to analyze if the use of CS systems reduce the need of blood products in low-risk patients undergoing cardiac surgery. METHODS Between February and June 2009 all low-risk patients (EuroSCORE<10%) undergoing coronary or valve procedure were selected (n=63). Exclusion criteria were: combined procedure, aorta procedure, redo surgery, emergency procedures, creatinine levels>2 mg/ml, anemic patients and patients with a body surface area (BSA)<1.6 m2. Patients were randomized to undergo cardiac surgery with a cell saving system (group CS) (n=34) or without (control group, CO) (n=29). All patients received tranexamic acid during the procedure. Need of blood products and clinical outcomes were analyzed in both groups. RESULTS Mean age was 64.7±12.3 years old with 33% of female patients. Baseline clinical characteristics and preoperative blood count cell were similar in both groups. Mean CS blood reinfused was 461±174 ml (maximum: 985 minimum: 259). A total of 59 red blood packages were transfused in 25 patients (mean 1.02±1.3; range: 0-5). The proportion of patients being transfused was similar in both groups (CS: 40% vs. CO: 46.4%; P=0.79). Eleven plasma packages were transfused (CS: 8 vs. CO: 3; P=0.77) and three platelet pools were used in group CS and none in group CO (P=0.08). Multivariate analysis showed that preoperative hemoglobin levels>13.3 g/dl [relative risk (RR): 0.29; confidence interval (CI): 0.09-0.99] and BSA>1.74 (RR: 0.19; CI: 0.54-0.68) were protective against blood transfusion. CONCLUSIONS In low-risk patients CS system did not reduce the need of blood transfusion. Clinical outcomes were similar regardless of the use of a cell saver system. A low preoperative hemoglobin level and a low BSA were related with the use of blood products.

Adjustable Segmental Tricuspid Annuloplasty: Technical Advantages and Midterm Results

BACKGROUND Adjustable segmental tricuspid annuloplasty is a new recently published procedure. The purpose of this prospective study was to present the technical advantages of this new tricuspid annuloplasty and analyze its early and midterm results. METHODS Between January 2004 and December 2006, 17 patients who had moderate or severe pure functional tricuspid regurgitation (TR) underwent adjustable segmental tricuspid annuloplasty. The mean age of the patients was 64.3 +/- 10.4 years and the majority were female (94%). All patients had recent preoperative transthoracic echocardiography (TTE). Three postoperative TTE were performed: (I) before the hospital discharge; (II) between 3 and 6 months after surgery; and (III) at a mean 30.4 +/- 13.8 months of follow-up. We studied the tricuspid valve, right ventricle, and left ventricle. RESULTS No hospital mortality was reported. Progressive overall clinical improvement was observed. Serial postoperative TTE revealed the following: (1) 13 patients with mild or less than mild TR, 1 patient with residual moderate TR, 1 patient with early moderate TR related to poor left ventricular function, and 1 patient with late severe TR due to a transvenous pacemaker lead; (2) the indexed tricuspid annulus diameter normalized in all patients; (3) pulmonary hypertension gradually regressed; and (4) right ventricular end-diastolic diameter and inferior vena cava diameter gradually decreased throughout the study. CONCLUSIONS Adjustable segmental tricuspid annuloplasty is an improved and efficient procedure for functional TR because it is more selective, more adjustable and more resistant. It may be adversely influenced by poor left ventricular function and by the presence of a pacemaker lead.

Bone marrow laser revascularisation for treating refractory angina due to diffuse coronary heart disease

To increase the angiogenic response and clinical efficacy of TMR, the potential synergy and safety of combining TMR with concentrated autologous bone marrow derived stem cells was evaluated. Fourteen patients with diffuse coronary artery disease and medically refractory class III/IV angina who were not candidates for conventional therapies were treated using TMR in combination with intramyocardial injection of concentrated stem cells. At the time of surgery, autologous bone marrow (120 cc) was aspirated from the iliac crest and processed over 15 min into 20 cc of concentrated mononuclear cells using a centrifugal system (HARVEST, Boston, MA). A single device performed holmium: YAG:TMR (CardioGenesis, Irvine, CA) with injection of 1 cc of concentrated stem cells through three multi-holed needles into the border zone around each laser channel. There were no perioperative adverse events including no arrhythmias. Mean number of injected cells per milliliter were: total mononuclear cells (81.3 x 10(6)), CD34(+) cells (0.6 x 10(6)), and CD133(+) cells (0.37 x 10(6)). At 7 months mean follow-up average angina class was significantly improved (3.5+/-0.5 vs 1.4+/-0.5; p=0.004). There was no death during the follow-up. Efficient delivery of stem cells combined with TMR in a single device seems to be safe and effective for treating unmanageable angina.

Restoration of atrial contractility after surgical cryoablation: clinical, electrical and mechanical results

To assess the electrical sinus rhythm (SR) recovery and the mechanical effectiveness of the atrial contraction by echocardiography is essential in patients undergoing atrial fibrillation (AF) surgery. Between September 2006 and May 2008, patients with chronic AF (n=33; permanent=23 or paroxysmal=10) underwent mitral surgery and surgical cryoablation for AF. Exclusion criteria were: AF that has persisted for 10 years and left atrium (LA) >65 mm. Echocardiography study was performed at six months after surgery. Mean age was 62 years (22 female, 11 male). Mean AF duration was three years (range 0.5-7.4). Mean atria size was 52.4+/-5.6 mm. Mitral valve surgery involved 32 prosthetic replacements and one mitral valve repair. There was no surgical mortality. Success rate for SR at three and six months was 90% and 82%, respectively. The only predictor of conversion to SR at six months was being at SR when discharge from the hospital. In patients in SR, echocardiographic study provided mechanical effectiveness of the atria in 100% of right atrium and 70% of the LA. Cryoablation for AF is an effective technique to recover electrocardiographic SR while being able to recover atrial contraction effectiveness.

Asymptotic behaviour of a generalized Burgers' equation

Abstract We consider the generalized Burgers equation: (GBE) u t =Δ(u m )− ∂ ∂x 1 (u q ), with exponents m>1 and q=m+(1/N). We study the large-time behaviour of nonnegative weak solutions of the Cauchy problem posed in Q= R N ×(0,∞) with integrable and nonnegative data. We construct a uni-parametric family {UM} of source-type solutions of (GBE) such that: U M (·,t)→M δ(x) in D ′ ( R N ) as t→0, and prove that they give the asymptotic behaviour of all solutions of the Cauchy problem. These special solutions have the following self-similar form: U(x,t)=t−αF(xt−β), with α=1/((m−1)+(2/N)) and Nβ=α. The criterion to choose the right member of the family is the following mass equality: M= ∫ R N u 0 d x . The construction of the family {UM} and the proof of the asymptotic convergence in this nonlinear, several dimensional setting needs a new method of asymptotic analysis. The results are then extended to equations of the form u t =ΔΦ(u)−∇· F (u), where Φ and F resemble the preceding power functions as u→0. In this more general case the asymptotic behaviour is described by the same family UM mentioned above.

Does use of cell saver decrease the inflammatory response in cardiac surgery

Background: The role of a cell-saver device in the inflammatory response to cardiac surgery has not been well documented. We hypothesized that the use of a cell saver may reduce proinflammatory cytokine concentrations in patients undergoing cardiac surgery. Methods: 57 patients presenting for first-time nonemergency cardiac surgery were prospectively randomized to control or cell salvage groups. Blood samples for inflammatory marker assays were collected from the arterial line on induction of anesthesia, at the end of cardiopulmonary bypass, 1 h after surgery, and 24 h after surgery. Plasma proinflammatory cytokines were analyzed using a sandwich solid-phase enzyme-linked immunosorbent assay. Results: The highest cytokine levels were observed 1 h after surgery. When comparing serum interleukin levels in both patient groups during the different perioperative periods, we found a higher interleukin-8 concentration 24 h after the procedure, and higher concentrations of the p40 subunit of interleukin-12 at 1 h and 24 h postoperatively. The concentrations of interleukin-6 and p40 were greater in blood stored by the cardiotomy suction system than in blood processed by the cell saver (p = 0.01 in both cases). The interleukin-8 concentration was higher in the blood processed by the cell saver (p = 0.03). No significant differences were observed in interleukin-1 and interferon gamma levels in blood from both systems. Clinical outcomes were similar in both groups. Conclusions: Our results suggest that cell salvage in low-risk patients undergoing their first elective cardiac procedure does not decrease the inflammatory response after surgery.

Outcomes of Aortic Valve Replacement According to Surgical Approach in Intermediate and Low Risk Patients: A Propensity Score Analysis

BACKGROUND Previous trials have shown that, among high-risk patients with aortic stenosis, survival rates are similar for transcatheter aortic-valve implantation (TAVI) and surgical aortic valve replacement. The study aimed to compare the outcomes of aortic valve replacement according to the adopted surgical approach in intermediate and low risk patients. METHODS This is a retrospective, observational, cohort study of prospectively collected data from 421 patients undergoing isolated aortic valve replacement between 2011 and 2015. A multinomial logit propensity score model based on preoperative risk factors was used to match patients 1:1:1 between conventional replacement (CAVR), minimally invasive (MIAVR) and TAVI groups, resulting in 50 matched three cohorts. RESULTS After multinomial logit propensity score, the three groups were comparable in terms of preoperative characteristics. Mean age and Logistic EuroSCORE I of CAVR, MIAVR and TAVI groups were (84.2±5.1 vs. 82.3±4.8 vs. 85.6±4.9 years; p=0.002) and (11.4±3.6% vs. 8.3±3.4% vs. 15.8±5.4%; p<0.001) respectively. Overall mortality rates were similar for the three patient cohorts at one year. There were no significant differences related to stroke to 30 days. In the TAVI cohort, pacemaker implantation for new-onset total atrioventricular block became necessary in 30% of patients (p<0.001) and 16% of patients had some degree of paravalvular aortic regurgitation, which was more than mild (p<0.001). Total length of stay was shorter in the TAVI group when compared with surgical groups (11.5±5.3 vs. 10.1±6.9 vs 8.5±3.7 days; p=0.023). After discharge, the survival rate follow-up (average follow up: 46.7 months) was 70%, 84% and 72% for three cohorts (log Rank x2=2.40, p=0.3). CONCLUSIONS In our experience, the three aortic valve replacement approaches offer very good results. Differences in the rate of complications were found between groups. Depending on patients characteristics the Heart-Team group must offer the best surgical approach for each patient.