Gideon Uretzky

Analyses of coronary graft patency after aprotinin use : results from the international multicenter aprotinin graft patency experience (IMAGE) trial

OBJECTIVE We examined the effects of aprotinin on graft patency, prevalence of myocardial infarction, and blood loss in patients undergoing primary coronary surgery with cardiopulmonary bypass. METHODS Patients from 13 international sites were randomized to receive intraoperative aprotinin (n = 436) or placebo (n = 434). Graft angiography was obtained a mean of 10.8 days after the operation. Electrocardiograms, cardiac enzymes, and blood loss and replacement were evaluated. RESULTS In 796 assessable patients, aprotinin reduced thoracic drainage volume by 43% (P < .0001) and requirement for red blood cell administration by 49% (P < .0001). Among 703 patients with assessable saphenous vein grafts, occlusions occurred in 15.4% of aprotinin-treated patients and 10.9% of patients receiving placebo (P = .03). After we had adjusted for risk factors associated with vein graft occlusion, the aprotinin versus placebo risk ratio decreased from 1.7 to 1.05 (90% confidence interval, 0.6 to 1.8). These factors included female gender, lack of prior aspirin therapy, small and poor distal vessel quality, and possibly use of aprotinin-treated blood as excised vein perfusate. At United States sites, patients had characteristics more favorable for graft patency, and occlusions occurred in 9.4% of the aprotinin group and 9.5% of the placebo group (P = .72). At Danish and Israeli sites, where patients had more adverse characteristics, occlusions occurred in 23.0% of aprotinin- and 12.4% of placebo-treated patients (P = .01). Aprotinin did not affect the occurrence of myocardial infarction (aprotinin: 2.9%; placebo: 3.8%) or mortality (aprotinin: 1.4%; placebo: 1.6%). CONCLUSIONS In this study, the probability of early vein graft occlusion was increased by aprotinin, but this outcome was promoted by multiple risk factors for graft occlusion.

Strict Thermoregulation Attenuates Myocardial Injury During Coronary Artery Bypass Graft Surgery as Reflected by Reduced Levels of Cardiac-Specific Troponin I

We assessed the cardioprotective effects of perioperative maintenance of normothermia by determining the perioperative profile of troponin I, a highly cardiac-specific protein important in risk stratification of patients with acute ischemic events. Candidates for their primary coronary artery bypass grafting (CABG) were randomized into a new thermoregulation system group, Allon( thermoregulation (AT; n = 30), and a routine thermal care (RTC; n = 30) group. Anesthetic and operative techniques were similar in both groups. Intraoperative warming was applied before and after cardiopulmonary bypass (CPB) and up to 4 h after surgery. Perioperative temperature and hemodynamic data were recorded. Blood samples for creatine kinase (CK) and its isoform, MB (CK-MB), and for cardiac-specific troponin I (cTnI) were obtained at predetermined intervals throughout the entire operation. Core and skin temperatures were higher in the AT group at all time points. The systemic vascular resistance was lower and the cardiac index higher in the AT group at all intra- and postoperative time points. Increases in CK, CK-MB, and cTnI levels indicated intraoperative ischemic insult in all patients. The respective CK levels for the AT and RTC groups were 53.3 +/- 22.7 IU/L and 47.9 +/- 17.86 IU/L at the time of anesthesia and 64.7 +/- 45.6 IU/L and 47.8 +/- 19.4 IU/L 30 min after the onset of surgery, demonstrating thereafter a steep increase before the discontinuation of CPB. CK-MB mass concentrations in both groups behaved almost identically. Pre-CPB cTnI levels at anesthesia induction were 0.3 +/- 0 ng/mL in both groups, followed by a distinctive profile observed after separation from CPB: 28.1 +/- 11.4 ng/mL, 26.05 +/- 9.20 ng/mL, and 22.3 +/- 8.9 ng/mL at discontinuation from CPB, chest closure, and 2 h after surgery, respectively, in the RTC group, versus 0.6 +/- 4.6 ng/mL, 6.6 +/- 5.5 ng/mL, and 7.9 +/- 4.76 ng/mL at these three time points, respectively, in the AT group (P < 0.01 between groups at the specified time points). Contrary to conventional thinking about the benefits of hypothermia, maintenance of normothermia throughout the non-CPB phases during CABG was demonstrated to be important in attenuating myocardial ischemic injury. Insofar as troponin I was more sensitive than other tested markers, it may provide important data on possible protection from myocardial insult and on other cardioprotective measures.

Pharmacokinetics of vancomycin administered as prophylaxis before cardiac surgery.

Vancomycin concentrations in serum, tissues, and sternum, administered as prophylaxis to patients during coronary artery bypass surgery, were measured. Vancomycin (15 mg/kg) was administered to 15 patients 1 hour before skin incision. Blood, tissue, and sternum samples were collected before, during, and after bypass. The concentration in serum at the end of infusion was 55.1 ± 22.8 &mgr;g/mL, the mean elimination half-life was 9 ± 4 hours, the areas under the concentration–time curve (AUC) from 0 to 12 hours and from 0 to infinity were 90.6 ± 25.1 and 289.7 ± 86.5 &mgr;g/h per mL, respectively, the mean residence time (MRT) was 11.9 ± 5.0 hours, the mean volume of distribution was 51.1 ± 12.2 L, and the total clearance was 78.3 ± 32.6 mL/min. Vancomycin concentrations in serum, tissues, and sternum during the operation were greater than the MIC90 for most staphylococci and ranged from 16 to 55 &mgr;g/mL in serum and from 4 to 39 &mgr;g/g in sternum and tissues.

Hemodynamic performance and outcome of percutaneous versus surgical stentless bioprostheses for aortic stenosis with anticipated patient-prosthesis mismatch.

OBJECTIVES We aimed to compare the performance and midterm survival of transcutaneous aortic valve replacement (TAVR) and surgically implanted stentless aortic valve replacement (SAVR) for severe aortic stenosis in patients anticipated to have patient-prosthesis mismatch (PPM). METHODS A retrospective analysis was performed of 86 and 49 consecutive TAVR and SAVR patients with severe aortic stenosis and calculated minimal effective orifice area larger than the best projected effective orifice area. Cox hazard analyses were used to assess the effect of TAVR versus SAVR on outcome. RESULTS The peak and mean transprosthetic gradient at discharge were lower (P < .001 for both) in the TAVR group. Mild or greater aortic regurgitation was more frequent in the TAVR group (61% vs 7%; P < .0001). At 3 months of follow-up, the mean gradient in the TAVR group was similar to that of the SAVR group but the prevalence of aortic regurgitation was still higher. The unadjusted 3-year survival rate was superior in the SAVR versus TAVR group (91.6% ± 4% vs 67.0% ± 7%; P = .01). Adjustments for both age and comorbidity resulted in loss of the difference in mortality between the 2 groups. CONCLUSIONS In patients with anticipated PPM, TAVR offers an immediate lower incidence of PPM than SAVR but a greater prevalence of aortic regurgitation. The differences in transaortic gradients became nonsignificant 3 months postoperatively. The question of whether TAVR is a suitable substitute for SAVR in patients with anticipated PPM, in particular, those who are older and sicker, warrants additional investigation.

Surgical Myocardial Revascularization versus Percutaneous Coronary Intervention with Drug-Eluting Stents in Octogenarian Patients

OBJECTIVE Our goal was to compare the clinical outcomes of octogenarian (or older) patients who are referred for either surgical or percutaneous coronary revascularization. METHODS We retrospectively evaluated the outcomes of all patients 80 years of age who had undergone coronary artery bypass grafting (CABG) with an internal mammary artery or had undergone a percutaneous coronary intervention (PCI) with a sirolimus-eluting stent to the left anterior descending artery in our center between May 2002 and December 2006. RESULTS Of the 301 patients, 120 underwent a PCI, and 181 underwent CABG. Surgical patients had higher rates of left main disease, triple-vessel disease, peripheral vascular disease, emergent procedures, and previous myocardial infarctions (39.7% versus 3.3% [P = .001], 76.1% versus 28.3% [P = .0001], 19.6% versus 7.5% [P = .004], 15.8% versus 2.5% [P = .0001], and 35.9% versus 25% [P = .04], respectively). CABG patients had a higher early mortality rate (9.9% versus 2.5%, P = .01). There were no differences in 1- and 4-year actuarial survival rates, with rates of 90% and 68%, respectively, for the PCI group and 85% and 71% for the CABG group (P = .85). The rates of actuarial freedom from major adverse cardiac events (MACEs) at 1 and 4 years were 83% and 75%, respectively, for the PCI group, and 86% and 78% for the CABG group (P = .33). The respective rates of freedom from reintervention were 87% and 83% for the PCI group, versus 99% and 97% for the CABG group (P < .001). The 4-year rate of freedom from recurring angina was 58% for the PCI group, versus 88% for CABG patients (P < .001). Revascularization strategy was not a predictor of adverse outcome in a multivariable analysis. CONCLUSION Octogenarian CABG patients were sicker and experienced a higher rate of early mortality. The 2 strategies had similar rates of late mortality and MACEs, with fewer reinterventions and recurring angina occurring following surgery.

Revascularization of the left anterior descending artery with drug-eluting stents: comparison with arterial off-pump surgery.

BACKGROUND This study compared early results of left anterior descending artery (LAD) stenting using drug-eluting stents (Cypher) with off-pump bilateral internal thoracic arterial (BITA) grafting. METHODS From June 2002 to June 2003, 200 consecutive patients underwent myocardial revascularization of the LAD territory, 100 by Cypher and 100 by BITA. The 2 groups were similar; however, left main disease and triple-vessel disease (20% and 75% versus 2% and 28%), age >70 (36% versus 17%) and intraaortic balloon pump (7% versus 0%) were more prevalent in the BITA group, and prior percutaneous coronary angiogplasty to the LAD was more prevalent in the Cypher group (28% versus 16%). RESULTS The number of coronary vessels treated per patient in the BITA group was higher (2.7 versus 1.45, P < .01). Thirty-day mortality was 1% in the BITA group and 0% in the Cypher group. Mean follow-up was 12 months. There was 1 late death in each group. Angina returned in 32% of the Cypher group and in 1% of the BITA group. There were 9 reinterventions in the Cypher group: 7 coronary angioplasties (including 2 to the LAD) and 2 surgical interventions. There was neither recurrent angina nor reintervention in the surgical group. CONCLUSIONS Despite a higher risk profile of patients treated with BITA, their clinical outcome is better. A longer and more complete angiographic follow-up is required to determine the role of drug-eluting stents in LAD revascularization.

Comparison between multivessel stenting with drug eluting to the LAD and bilateral internal thoracic artery grafting.

BACKGROUND Reduction of restenosis and reinterventions was reported with drug-eluting stents (Cypher). This study compares results of multivessel Cypher stenting with bilateral internal thoracic artery (BITA) grafting. METHODS From January 2002 to June 2004, 725 consecutive patients underwent multivessel myocardial revascularization, 95 by 2 or more Cypher stents and 630 by BITA. After matching for age, sex, and extent of coronary artery disease, 2 groups (87 patients each) were used to compare the 2 revascularization modalities. RESULTS The 2 groups were similar; however, left main and the use of an intra-aortic balloon pump were more prevalent in the BITA group. The number of coronary vessels treated per patient was higher in the BITA group (2.71 versus 2.24 for BITA and Cypher, respectively; P = .001). Mean follow-up was 12 months. Thirty-day mortality was 0 in both groups. There were no late deaths in the BITA group and 2 (2.3%) in the Cypher group (P value was not significant). Angina returned in 29.9% of the Cypher group and 12.6% of the BITA group (P = .005). Multivariable Cox analysis revealed percutaneous intervention (PCI) (Cypher group) to be the only independent predictor of angina recurrence (Odds Ratio 2.62, 95% Confidence Interval 1.11-6.17). There were 10 reinterventions (PCI) in the Cypher group compared to 5 in the BITA group. One-year reintervention-free survival (Kaplan-Meier) of the BITA group was 96% compared to 88% in the Cypher group (P = .015). CONCLUSIONS Midterm clinical outcome of surgically treated patients is still better. However, the reintervention gap between surgery and percutaneous interventions was reduced by treating 2 or more coronary vessels with Cypher stents.

The intra-aortic cannula pump: A novel assist device for the acutely failing heart

OBJECTIVE The intra-aortic cannula pump is a catheter pump designed to support the acutely failing heart. It expels blood from the left ventricle into the ascending aorta in a pulsatile flow pattern. The aim of the study was to analyze the hemodynamic performance of this new intracardiac support system in acute heart failure. METHODS A 24F cannula was studied in a series of 16 sheep. Hemodynamic changes were assessed in the nonfailing, the moderately failing, and the severely failing heart. Heart failure was induced by an injection of microspheres into the left anterior descending coronary artery. The cannula was inserted through the aortic arch and introduced through the aortic valve into the left ventricle. RESULTS Cannula insertion was feasible in all animals. Flow through the intra-aortic cannula flow was increased to a maximum of 3 L/min. No hemodynamic changes were observed in the nonfailing heart. A significant increase in cardiac output was observed in the moderately and severely reduced left ventricle (2.67 +/- 0.7 L to 3.51 +/- 0.83 L; P =.001; and 1.18 +/- 0.77 L to 2.43 +/- 0.44 L; P =.001, respectively). A drop in left atrial pressure was achieved in moderate and severe heart failure (14.1 +/- 5.93 mm Hg to 9.71 +/- 2.63 mm Hg; P =.0001; and 23 +/- 7.16 mm Hg to 11.2 +/- 2.55 mm Hg; P = 0.0001, respectively). Systolic and diastolic systemic blood pressures increased in the severely failing heart (57.3 +/- 12.8 mm Hg to 75.4 +/- 11.2 mm Hg; P =.0001; and 35.6 +/- 8.2 mm Hg to 60 +/- 14.3 mm Hg; P =.0006, respectively). CONCLUSIONS Hemodynamic data demonstrate the beneficial effects of the intra-aortic cannula pump in moderate and severe heart failure. The intra-aortic cannula pump represents a new modality for the treatment of acute heart failure.

Off-Pump Coronary Revascularization of the Circumflex System: Comparison between Sequential and Nonsequential Arterial Grafts

BACKGROUND Sequential grafting increases the availability of arterial grafts. This study aims to determine the safety and efficacy of sequential grafting of the circumflex coronary distribution performed off-pump. METHODS Between 2000 and 2003, 136 patients undergoing off-pump sequential arterial grafting of the circumflex territory were compared to 278 patients who received nonsequential grafts to the same area. RESULTS The grafts/patient ratio was higher in the sequential than the nonsequential group (3.2 +/- .4 and 2.3 +/- .2, respectively, P < .0001). Radial artery conduits and T-grafts were used more often in the sequential group; conversely, bilateral internal thoracic artery configurations were more frequent in the nonsequential groups (P < .0001). There were 1.2 sequential anastomoses per patient. Early mortality (2.2% versus 2.5%), myocardial infarction (2.2% versus 1.1%) and stroke (.7% versus none) rates were comparable. Use of sequentials or other operative confounders had no independent effect on the occurrence of early adverse events (stepwise logistic regression). At 3.5 years, survival was 95.9% and 84.2% in the sequential and nonsequential groups, respectively (P = .231, log-rank). Despite comparable incidence of major adverse cardiac events (MACE) (6.6% versus 8.6%, P = .470) and similar 3.5-year freedom from MACE (88.7% for both groups, P = .682), Cox regression analysis identified sequential grafting as an independent predictor of MACE (P < .0001, HR 19.9), increasing this risk by 20-fold. CONCLUSIONS Off-pump sequential grafting of the circumflex system may be safely performed. The use of sequentials, however, had an independent effect on increased midterm MACE. The distribution of events suggests culpability of surgical factors and may reflect a learning curve.

Transapical Implantation of a Melody Valve in a Degenerated Low-Diameter Prosthetic Aortic Valve

78-year-old woman had undergone a biological aortic valve replacement (Mitroflow Pericardial, Sorin Inc, Burnaby, BC, Canada) and coronary artery bypass graft surgery 8 years previously. Acute exacerbation of her symptoms resulting from prosthetic aortic valve stenosis caused respiratory failure, necessitating resuscitation and mechanical ventilation. A transthoracic Doppler echocardiogram demonstrated peak and mean prosthetic aortic valve gradients of 70 and 51 mm Hg, respectively, and a calculated valve area of 0.5cm 2 (Figure 1). Coronary angiography demonstrated triple-vessel disease and 3 patent grafts to all coronary territories. Although the need for a tracheostomy and the seeming adherence of patent grafts to the sternal plate precluded conventional surgical intervention, the prosthetic valve size of 19 mm deemed the patient unsuitable for a conventional transcatheter aortic valve implantation. A Melody valve (Medtronic Inc, Santa Ana, CA), because of its suitability for annular diameters of 16 to 22 mm, was a possible solution. A surgical transapical approach was chosen because of the limitations of the Melody transvenous delivery system, poor vascular access, and the need for absolute control during the procedure. A pediatric cardiologist (E.B.) familiar with the Melody system was integrated into the team. The valve delivery system, Ensemble, is a balloon-in-balloon over-the-wire catheter onto which the valve is hand crimped. The level of expansion of the valve is determined by the size of the outer balloon used for inflation (range, 18–22 mm). The balloon and Melody valve are covered by a movable sleeve that is retracted before positioning and deployment with 22F profile that could easily be advanced through a 24F Ascendra-2 transapical sheath (Ascendra Inc, Reston, VA) originally designed for Edwards-XT transcatheter aortic valve implantation with its radiopaque markers and a reliable hemostatic seal. The femoral vessels were accessed for transvenous pacing and an aortic root marker pigtail catheter. The working angle was determined to be perpendicular to the Mitroflow ring (Figures 2 and 3). To avoid unequal valve expansion and to verify the true inner diameter of Mitroflow, we predilated the stenotic valve with a Nucleus 18-mm balloon (NuMed Inc, Hopkington, NY; Figure 4). After the valvuloplasty, the Melody delivery system was introduced via the Ascendra-2 sheath and positioned in a 50:50 position through the valve