Enhanced preservation of pig cardiac allografts by combining erythropoietin with glyceryl trinitrate and zoniporide.

Erythropoietin has a tissue-protective effect independent of its erythropoietic effect that may be enhanced by combining it with the nitric oxide donor glyceryl trinitrate (GTN) and the sodium-hydrogen exchange inhibitor zoniporide in rat hearts stored with an extracellular-based preservation solution (EBPS). We thus sought to test this combination of agents in a porcine model of orthotopic heart transplantation incorporating donor brain death and total ischaemic time of approximately 260 min. Pig hearts were stored in one of four storage solutions: unmodified EBPS (CON), EBPS supplemented with GTN and zoniporide (GZ), EBPS supplemented with erythropoietin and zoniporide (EZ), or EBPS supplemented with all three agents (EGZ). A total of 4/5 EGZ hearts were successfully weaned from cardiopulmonary bypass compared with only 2/5 GZ hearts, 0/5 CON hearts and 0/5 EG hearts (p = 0.017). Following weaning from bypass EGZ hearts demonstrated superior contractility and haemodynamics than GZ hearts. All weaned hearts displayed impaired diastolic function. Release of troponin I from EGZ hearts was lower than all other groups. In conclusion, supplementation of EBPS with erythropoietin, glyceryl trinitrate and zoniporide provided superior donor heart preservation than all other strategies tested.

Individual patient meta-analysis of exercise training effects on systemic brain natriuretic peptide expression in heart failure.

BACKGROUND: Brain natriuretic peptide (BNP) predicts exercise performance and exercise training may modulate BNP and its N-terminal portion (NT-pro-BNP), we therefore conducted an individual patient analysis of exercise training effects on BNP and NT-pro-BNP. AIMS: To use an individual patient meta-analysis to relate changes in BNP, NT-pro-BNP, and peak VO(2); to link these changes to volume parameters of exercise training programmes (intensity etc.); and to identify patient characteristics likely to lead to greater improvements in BNP, NT-pro-BNP, and peak VO(2). DESIGN: Individual patient meta-analysis. METHODS: A systematic search was conducted of Medline (Ovid), Embase.com, Cochrane Central Register of Controlled Trials, and CINAHL (until July 2008) to identify randomized controlled trials of aerobic and/or resistance exercise training in systolic heart failure patients measuring BNP and/or NT-pro-BNP. Primary outcome measures were change in BNP, NT-pro-BNP, and peak VO2. Subanalyses were conducted to identify (1) patient groups that benefit most and (2) exercise programme parameters enhancing favourable changes in primary outcome measures. RESULTS: Ten randomized controlled studies measuring BNP or NT-pro-BNP met eligibility criteria, authors provided individual patient data for 565 patients (313 exercise and 252 controls). Exercise training had favourable effects on BNP (-28.3%, p < 0.0001), NT-pro-BNP (-37.4%, p = < 0.0001), and peak VO(2) (17.8%, p < 0.0001). The analysis showed a significant change in primary outcome measures; moreover, change in BNP (r = -0.31, p < 0.0001) and NT-pro-BNP (r = -0.22, p < 0.0001) were correlated with peak VO(2) change. CONCLUSION: Exercise training has favourable effects on BNP, NT-pro-BNP, and peak VO(2) in heart failure patients and BNP/NT-pro-BNP changes were correlated with peak VO(2) changes.

Combining cariporide with glyceryl trinitrate optimizes cardiac preservation during porcine heart transplantation.

Sodium-hydrogen exchange inhibitors, such as cariporide, are potent cardioprotective agents, however, safety concerns have been raised about intravenously (i.v.) administered cariporide in humans. The aim of this study was to develop a preservation strategy that maintained cariporide's cardioprotective efficacy during heart transplantation while minimizing recipient exposure. We utilized a porcine model of orthotopic heart transplantation that incorporated donor brain death and 14 h static heart storage. Five groups were studied: control (CON), hearts stored in Celsior; CAR1, hearts stored in Celsior with donors and recipients receiving cariporide (2 mg/kg i.v.) prior to explantation and reperfusion, respectively; CAR2, hearts stored in Celsior supplemented with cariporide (10 mumol/L); GTN, hearts stored in Celsior supplemented with glyceryl trinitrate (GTN) (100 mg/L); and COMB, hearts stored in Celsior supplemented with cariporide (10 mumol/L) plus GTN (100 mg/L). A total of 5/5 CAR1 and 5/6 COMB recipients were weaned from cardiopulmonary bypass compared with 1/5 CON, 1/5 CAR2 and 0/5 GTN animals (p = 0.001). Hearts from the CAR1 and COMB groups demonstrated similar cardiac function and troponin release after transplantation. Supplementation of Celsior with cariporide plus GTN provided superior donor heart preservation to supplementation with either agent alone and equivalent preservation to that observed with systemic administration of cariporide to the donor and recipient.

Long-term clinical follow-up of sirolimus-eluting (CYPHER) coronary stents in the treatment of instent restenosis in an unselected population.

Randomised trials in a highly selected patient population have demonstrated a dramatic reduction in the incidence of in-stent restenosis (ISR) following implantation of sirolimus-eluting (S-E) Cypher coronary stents compared with bare metal stents (BMS). The clinical outcome following implantation of S-E stents for treatment of complex, unselected BMS ISR is less well defined. The aim of this study was to assess the safety and efficacy of S-E coronary stents in the treatment of an unselected population of BMS ISR. All patients who received S-E stents for treatment of BMS ISR from May 1 2002-November 30 2003 at a single institution were entered into a prospectively collected database. In-hospital and long-term outcomes were collected. Sixty patients were identified who received S-E stents for the treatment of ISR. Four patients (6%) had undergone previous brachytherapy and 22% were diabetic. The most common target vessel was the left anterior descending coronary artery (40%), and 6% of lesions were in saphenous vein grafts (SVGs). The mean reference diameter was 2.67+/-0.52 (range 1.75-4.0) mm and the mean lesion length was 16.22+/-11.46 (range 3-68) mm. There were no procedural or in-hospital major adverse cardiac events (MACE). Long-term follow-up was available in 59 patients (98%). The 12-month MACE rate (cardiac death, myocardial infarction or target lesion revascularisation) was 12% with a 7% percutaneous coronary intervention rate and a 7% coronary artery bypass graft rate. There were no cardiac deaths and two non-cardiac deaths. Of the seven patients who had clinical restenosis at 12 months, four had previously failed brachytherapy and three involved SVGs. In conclusion, the use of S-E stents appears safe and efficacious in the treatment of an unselected population of BMS ISR with results comparing favourably with historical controls. Further randomised studies are needed to delineate the optimal management of this high risk group of patients.

Clinical follow-up of paclitaxel-eluting (TAXUS) stents for the treatment of saphenous vein graft disease.

BACKGROUND: Randomized trials in selected patient populations have demonstrated dramatic reductions in the incidence of in-stent restenosis (ISR) following implantation of paclitaxel-eluting (PE) coronary stents compared with bare metal stents in native coronary disease. The clinical outcome following implantation of PE stents for saphenous vein graft (SVG) stenosis is largely unknown. AIM: To assess the safety and efficacy of PE coronary stents for the treatment of SVG stenosis in an unselected population. METHODS: All patients who received PE stents for the treatment of SVG disease from May 1, 2003, to May 1, 2005, were entered into a prospectively collected database. Fifty-five patients were identified with 69 lesions. In-hospital and late major adverse cardiac events (MACE) including death, myocardial infarction (MI), and target lesion revascularization (TLR) were recorded as well as the rate of target vessel revascularization (TVR). RESULTS: Mean follow-up was 13 months with 54 of the 55 patients contacted. The number of stents implanted was 1.12 +/- 0.37 per lesion and 1.38 +/- 0.59 per patient. Clinically significant procedural MACE was 0%. The late MACE rate was 9% with a 2% clinically driven TLR, a 4% coronary artery bypass graft (CABG), and a 4% TVR rate. There were four deaths, two cardiac and two noncardiac. CONCLUSION: PE stents appear safe and effective in the treatment of SVG disease at a mean follow-up time of 13 months. Randomized studies are needed to further delineate the optimal management of this high-risk group.

The effects of hormone resuscitation on cardiac function and hemodynamics in a porcine brain-dead organ donor model.

We compared the effects of hormone resuscitation (HR) with a norepinephrine-based protocol on cardiac function, hemodynamics and need for vasopressor support after brain death in a porcine model. Following brain death induction, animals were treated with norepinephrine and fluids for 3 h. In the following 3 h, they continued on norepinephrine and fluids (control) or received additional HR (triiodothyronine, methylprednisolone, vasopressin, insulin). Data were collected pre-brain death, 3 and 6 h post-brain death. At 6 h, median norepinephrine use was higher in controls (0.563 vs. 0 microg/kg/min; p < 0.005), with 6/8 HR animals weaned off norepinephrine compared with 0/9 controls. Mean arterial pressure was higher in HR animals at 6 h (74 +/- 17 vs. 54 +/- 14 mmHg; p < 0.05). Cardiac contractility was also significantly higher in HR animals at 6 h (stroke work index 1.777 vs. 1.494). After collection of 6 h data, all animals were placed on the same low dose of norepinephrine. At 6.25 h, HR animals had higher stroke work (3540 +/- 1083 vs. 1536 +/- 702 mL.mmHg; p < 0.005), stroke volume (37.2 +/- 8.2 vs. 21.5 +/- 9.8 mL; p < 0.01) and cardiac output (5.8 +/- 1.4 vs. 3.2 +/- 1.2 L/min; p < 0.005). HR in a porcine model of brain death reduces norepinephrine requirements, and improves hemodynamics and cardiac function. These results support the use of HR in the management of the brain-dead donor.

A systematic review of the safety of analgesia with 50% nitrous oxide: can lay responders use analgesic gases in the prehospital setting?

A safe and effective form of pain relief would be an advantage in the prehospital treatment of patients experiencing extreme pain. Although used by many emergency medical services, 50% nitrous oxide (an inhaled analgesic known to have good pain relief properties) is not widely used by volunteer and semiprofessional organisations. This review aimed to determine whether 50% nitrous oxide is safe for use by first responders who are not trained as emergency medical technicians. A thorough search of the literature identified 12 randomised controlled trials investigating the use of 50% nitrous oxide (as compared with placebo or conventional analgesic regimens) in a range of conditions. The outcomes analysed for this review were: adverse events, recovery time, and need for additional medication. None of the studies compared the treatments in the prehospital setting; children were well represented. Adverse effects were rare and significant adverse outcomes such as hypotension and oxygen desaturation could not be attributed to nitrous oxide. Compared with patients receiving conventional analgesia, those receiving 50% nitrous oxide did not require additional medication any more frequently and had a faster recovery from sedative effects. The low incidence of significant adverse events from 50% nitrous oxide suggests that this agent could be used safely by lay responders.