Early Gastrointestinal Complications From Ventricular Assist Devices is Increased by Non-Pulsatile Flow.

BACKGROUND: Measurements of organ flow and perfusion during cardiopulmonary bypass suggest that perfusion of the splanchnic bed can be impaired by non-pulsatile flow. We postulated that non-pulsatile flow from centrifugal ventricular assist devices might also compromise splanchnic blood flow and cause bowel ischaemia especially in the period of circulatory instability early post-implant. The aim of the present studies was to compare the incidence of gastrointestinal (GI) complications in patients having a non-pulsatile device with the incidence in those having a pulsatile device. METHODS: In a pilot study, the initial 12 patients who received the Ventrassist (Ventracor, Sydney, NSW, Australia) centrifugal, non-pulsatile device during the period from June 2003 to September 2005 at the Alfred Hospital, Melbourne were compared with 11 patients who received a Thoratec (Thoratec, Pleasanton, CA, USA), pulsatile, positive displacement device and the incidence was recorded of GI complications requiring an intervention either surgical, endoscopic or by interventional radiology. This was followed by a larger (full) study of a second cohort of similar ventricular assist device (VAD) patients from January 1992 until December 2012 comparing 53 patients having non-pulsatile devices and 110 having pulsatile devices. RESULTS: In the pilot study, the overall incidence of complications in the non-pulsatile group (67%) was almost double that in the pulsatile group (36%) but the difference was not statistically significant (p = 0.15) because of the small number (n = 23) of participants. In the full study, all GI complications with either device occurred within the first 3 weeks post-implant. In the non-pulsatile patients, there was a higher incidence of GI bleeding, 23% vs 4% (p = 0.002), endoscopies, 24% vs 12% (p = 0.049). More patients with a non-pulsatile flow device had delayed absorption of nasogastric feeds than their pulsatile counterparts, 35% vs 7% (p < 0.0001). Patients with a non-pulsatile flow device had a higher overall rate of gastrointestinal complications than patients had with a pulsatile flow device, 56% vs 20% (p < 0.0001). After correcting for the other predictors, the odds of developing a gastrointestinal complication in the pulsatile group was significantly lower (odds ratio 0.07) than in the non-pulsatile device group (p < 0.0001). CONCLUSIONS: We conclude that the use of non-pulsatile centrifugal VADs compared with pulsatile positive displacement VADs is associated with a higher incidence of both haemorrhagic and ischaemic complications in the gastro-intestinal system especially in the very early post-implant period. Whether these complications could be reduced in centrifugal devices by increasing their pulsatility is not clear and merits further research.

Physical conditioning and mental stress reduction--a randomised trial in patients undergoing cardiac surgery.

BACKGROUND: Preoperative anxiety and physical unfitness have been shown to have adverse effects on recovery from cardiac surgery. This study involving cardiac surgery patients was primarily aimed at assessing the feasibility of delivering physical conditioning and stress reduction programs within the public hospital setting. Secondary aims were to evaluate the effect of these programs on quality of life (QOL), rates of postoperative atrial fibrillation (AF) and length of stay (LOS) in hospital. METHODS: Elective patients scheduled for coronary artery bypass graft and/or valve surgery at a public hospital in Melbourne, Australia were enrolled. Patients were randomized to receive either holistic therapy (HT) or usual care (UC). HT consisted of a series of light physical exercise sessions together with a mental stress reduction program administered in an outpatient setting for the first two weeks after placement on the waiting list for surgery. A self-administered SF-36 questionnaire was used to measure QOL and hospital records to collect data on LOS and rate of postoperative AF. RESULTS: The study population comprised 117 patients of whom 60 received HT and 57 received UC. Both programs were able to be delivered within the hospital setting but ongoing therapy beyond the two week duration of the program was not carried out due to long waiting periods and insufficient resources. HT, as delivered in this study, compared to UC did not result in significant changes in QOL, LOS or AF incidence. CONCLUSIONS: Preoperative holistic therapy can be delivered in the hospital setting, although two weeks is insufficient to provide benefits beyond usual care on QOL, LOS or postoperative AF. Further research is now required to determine whether a similar program of longer duration, or targeted to high risk patients can provide measurable benefits. TRIAL REGISTRATION: This trial was conducted as part of a larger study and according to the principles contained in the CONSORT statement 2001.

Perioperative metabolic therapy improves redox status and outcomes in cardiac surgery patients: a randomised trial.

OBJECTIVE: Perioperative therapy with antioxidants and metabolic substrates has the potential to reduce oxidative stress and improve recovery from cardiac surgery, particularly in elderly and high risk cases. The aim of this study was to assess the effect of perioperative metabolic therapy at a biochemical, clinical and economic level in cardiac surgical patients. METHODS: Patients (n=117, mean age 65 ± 1.0 years, 74% male) undergoing elective coronary artery bypass graft (CABG) and/or valve surgery in 2004-2006 were randomised to receive in double blinded fashion, while on the waiting list for surgery (approximately two months) and one month after surgery, either metabolic therapy (coenzyme Q(10), magnesium orotate, lipoic acid, omega-3 fatty acids and selenium) or placebo. Biochemical and clinical outcomes were assessed. RESULTS: Cardiac surgery increased oxidative stress and decreased plasma levels of key antioxidants. Metabolic therapy for a mean of 76 ± 7.5 days increased antioxidant levels preoperatively so that the adverse effect of surgery on redox status was attenuated. Metabolic therapy reduced plasma troponin I, 24 hours postoperatively from 1.5 (1.2-1.8) (geometric mean 95% CI) µg/L, to 2.1 (1.8-2.6) µg/L (P=0.003) and shortened the mean length of postoperative hospital stay by 1.2 days from 8.1 (7.5-8.7) to 6.9 (6.4-7.4) days (P=0.004) and reduced hospital costs. Metabolic therapy was inexpensive and had no clinically significant side effects. CONCLUSIONS: Perioperative metabolic therapy for cardiac surgery is safe and inexpensive and is associated with improved redox status, reduced myocardial damage, and shortened length of postoperative hospital stay.

Skeletonized internal thoracic artery harvesting reduces chest wall dysesthesia after coronary bypass surgery.

OBJECTIVE: A pain syndrome related to intercostal nerve injury during internal thoracic artery harvesting causes significant morbidity after coronary bypass surgery. We hypothesized that its incidence and severity might be reduced by using skeletonized internal thoracic artery harvesting rather than pedicled harvesting. METHODS: In a prospective double-blind clinical trial, 41 patients undergoing coronary bypass were randomized to receive either unilateral pedicled or skeletonized internal thoracic artery harvesting. Patients were assessed 7 (early) and 21 (late) weeks postoperatively with reproducible sensory stimuli used to detect chest wall sensory deficits (dysesthesia) and with a pain questionnaire used to assess neuropathic pain. RESULTS: At 7 weeks postoperatively, the area of harvest dysesthesia (percentage of the chest) in the skeletonized group (n = 21) was less (median, 0%; interquartile range, 0-0) than in the pedicled group (n = 20) (2.8% [0-13], P = .005). The incidence of harvest dysesthesia at 7 weeks was 14% in the skeletonized group versus 50% in the pedicled group (P = .02). These differences were not sustained at 21 weeks, as the median area of harvest dysesthesia in both groups was 0% (P = .89) and the incidence was 24% and 25% in the skeletonized and pedicled groups, respectively (P = 1.0). The incidence of neuropathic pain in the skeletonized group compared with the pedicled group was 5% versus 10% (P = .6) at 7 weeks and 0% versus 0% (P = 1.0) at 21 weeks. CONCLUSIONS: Compared with pedicled harvesting, skeletonized harvesting of the internal thoracic artery provides a short-term reduction in the extent and incidence of chest wall dysesthesia after coronary bypass, consistent with reduced intercostal nerve injury and therefore the reduced potential for neuropathic chest pain.

Antioxidant therapy for severe cardiac failure induced by iron overload secondary to dyserythropoietic anaemia.

We present a case of a patient with longstanding transfusion-dependent congenital dyserythropoietic anaemia (CDA) who developed cardiomyopathy despite iron chelation therapy. She presented with severe heart failure that responded poorly to conventional therapy, recovering only when therapy was augmented with metabolic agents including antioxidants and with increased iron chelation. The present case gives support to the concept of treating oxidatively induced heart failure with metabolic and antioxidant therapy. This therapy may have wider application in refractory heart failure and in the prevention of cardiomyopathy in patients receiving regular red cell transfusions who are at risk of transfusional haemosiderosis.