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Biomedical subjects

Massimo Caputo

Publications and source records attributed to Massimo Caputo.

At least 19 recordsLinked to original sources
PubMed2006

Changes in myocardial free amino acids during pediatric cardiac surgery: a randomised controlled trial of three cardioplegic techniques.

OBJECTIVE: The developing heart has a much greater dependence on amino acid (AA) metabolism than the adult heart in determining its ischemic tolerance. Blood cardioplegia preserves myocardial free AAs in adult hearts but no clinical studies have looked at the effect of different cardioplegic techniques on intracellular free AAs in the pediatric heart. METHODS: Pediatric patients were randomised to receive intermittent antegrade cold crystalloid (CC), cold blood (CB) or cold blood cardioplegia with a 'hot shot' (CB+HS). Right ventricular biopsies were collected prior to ischemia, at the end of ischemia and 20 min after reperfusion. Amino acid levels were analysed as repeated measures, adjusting for baseline levels. Data were analysed separately for acyanotic and cyanotic patients. RESULTS: Of 103 patients recruited, 32 (22 acyanotic and 10 cyanotic), 36 (24/12) and 35 (25/10), respectively were allocated to CC, CB and CB+HS groups. Cyanotic patients were significantly younger with longer cross-clamp times. In acyanotic patients, there were no significant effects of cardioplegic method on aspartate, glutamine, taurine, alanine or branched chain AA levels (all p>0.05). However, in cyanotic patients, there were significant interactions of cardioplegic method and time (all p<0.05) for all amino acids, with patients allocated to CB+HS having higher levels after reperfusion compared with CC, and patients allocated to CB having intermediate levels. CONCLUSIONS: For cyanotic patients (younger, longer cross-clamp times), CB+HS preserves myocardial free AAs better than CC; CB gives an intermediate effect. In acyanotic patients, AA levels (all p>0.15) and group means were similar both at the end of ischemia and after reperfusion.

Age Factors↗
PubMed2006

Morbidity and mortality following acute conversion from off-pump to on-pump coronary surgery.

OBJECTIVE: Many studies have described reduced morbidity in hospital and equivalent midterm outcomes with off-pump coronary artery bypass (OPCAB) surgery compared to conventional CABG (CABG-CPB). However, OPCAB is sometimes converted acutely to CABG-CPB. We describe the risk of acute conversion and compare patients' outcomes for acutely converted OPCAB with unconverted OPCAB and CABG-CPB. METHODS: Consecutive acute conversions, i.e. OPCAB patients in whom CPB was instituted urgently for hemodynamic or electrical instability, cardiac arrest or uncontrolled bleeding, were compared with propensity-matched unconverted OPCAB and CABG-CPB patients. Relative risks of death and complications in hospital, and subsequent survival were estimated. RESULTS: The risk of acute conversion between 1996 and 2004 was 1.1% (27/2492): 5.1% in the first 2 years, 2.2% in the third year and 0.8% subsequently. Odds ratios for death in hospital compared to unconverted OPCAB and CABG-CPB were 4.4 (95% confidence interval (CI) 0.67-29.1) and 4.7 (95% CI 1.03-21.1), respectively, and ranged from 0 to 4.5 for serious complications. Converted patients had an increased hazard of death for 3 years after surgery compared to unconverted OPCAB (hazard ratio 3.21, 95% CI 1.20-8.59) and CABG-CPB patients (hazard ratio 3.23, 95% CI 1.41-7.39). CONCLUSIONS: Experienced OPCAB surgeons have a low risk of acute conversion. Acutely converted patients have a moderately increased risk of death and serious complications in hospital. These risks are difficult to quantify precisely because conversion is rare.

Aged↗
PubMed2006

Free amino acids in hearts of pediatric patients with congenital heart disease: the effects of cyanosis, age, and pathology.

BACKGROUND: The immature heart has a much greater dependence than the adult heart on amino acid transamination in determining its ischemic tolerance. Compared with adult hearts, experimental models of the immature heart have quantified higher resting concentrations of free amino acids (AA) which are depleted by acute hypoxia. However, we have found no clinical studies that have looked at the free AA profile of the immature human heart or the effects of cyanosis, age, and pathology upon this. METHODS: One hundred eighty-one pediatric patients (37 cyanotic, 144 acyanotic) undergoing open-heart surgery were recruited. Myocardial biopsies were collected prior to ischemia and analyzed for free AAs (eg, glutamate, aspartate) using high-performance liquid chromatography. The effects of cyanosis, age, and pathology on amino acid concentrations were estimated by multiple regression modeling with and without controlling for diagnosis; the effects of age and pathology were estimated only in acyanotic children. RESULTS: Alanine concentrations were about 20% higher in cyanotic than acyanotic patients (p = 0.04). Cyanosis was not associated with any other amino acid levels. In acyanotic patients, after controlling for diagnosis, concentrations of glutamate, aspartate, and alanine decreased from birth to about 8 to 10 years, then started to increase again (p < 0.05 for both linear and quadratic terms); concentrations of taurine and the branched chain AAs decreased steadily with increasing age (p < 0.05). There were significant effects of pathology on glutamate (p = 0.006), glutamine (p = 0.003), and branched chain AA (p = 0.004) levels. CONCLUSIONS: There is no evidence that chronic hypoxia depletes endogenous AAs. Young age is associated with higher resting AA levels.

Aging↗
PubMed2006

Ascending aorta or arch surgery: is previous cardiac surgery a risk factor?

Surgery on the ascending aorta +/- arch is a challenge. The risks involved in such operations after previous cardiac surgery were assessed in elective and emergency settings in a single institution. Over a 10-year period, 29 patients underwent replacement of the ascending aorta +/- arch following previous cardiac surgery. In 12 patients (41.4%), the procedure was carried out on an emergency basis. Thirteen had previous replacement of the ascending aorta and 16 had previous valve replacement with or without coronary artery bypass; 4 patients were undergoing a 3rd cardiac operation. Concomitant procedures included coronary artery bypass in 2, arch replacement in 4, and descending aortic replacement in one. The overall in-hospital mortality was 13.8% (4/29) vs. 12.4% (33/267) in primary procedures. Mortality in elective repeat surgery was 5.9% (1/17) vs. 25% (3/12) in emergency re-operations. The incidences of permanent stroke (3.4%) and renal failure (3.4%) were similar to first-time operations. Elective re-operation for ascending aorta +/- arch repair can be accomplished with acceptable mortality and morbidity. Outcomes in emergency cases carry a higher early mortality but still conform to contemporary expectations and are similar to emergency first-time aortic surgery.

Aged↗
PubMed2005

Prosthetic valve endocarditis.

Prosthetic valve endocarditis is a catastrophic complication of cardiac valve replacement, associated with high mortality rates. Medical treatment is effective in a few instances of endocarditis involving the leaflets alone in bioprostheses. However, accurate diagnosis, better myocardial protection, and improved surgical strategies have led to better survival in patients undergoing surgery after failed conservative therapy. This comprehensive review addresses various issues involved in the management of this complication.

Anti-Bacterial Agents↗
PubMed2005

Acquiring proficiency in off-pump surgery: traversing the learning curve, reproducibility, and quality control.

As the risk profile of patients considered for surgical revascularization worsens, the cumulative benefit of off-pump coronary artery bypass (OPCAB) over conventional coronary artery bypass grafting, in terms of lower morbidity and reduced healthcare costs, may increase. There is still resistance to the introduction of OPCAB surgery however, its practice is variable and surgical residents are rarely trained in these techniques. This article considers how the learning curve in OPCAB may be negotiated and prospectively monitored to ensure quality control. The evidence suggests that situations in which suitable senior expertise exists, OPCAB surgery can be introduced into surgical practice and safely taught to trainees without detriment to patients. This is achieved by a progressive increase in the complexity of the case mix and careful early supervision. The introduction of OPCAB has coincided with the increasing use of control charts as quality control tools. Performance monitoring provides reassurance that patients are not being put at risk during the introduction of OPCAB; control chart methods can be used prospectively for real time performance monitoring by consultant surgeons and residents alike. These techniques may ultimately be used to determine proficiency and accreditation. Increasing use of parallel training techniques, the development of structured training programs that encompass OPCAB and other new technologies in cardiac surgery, coupled with objective performance monitoring are warranted to meet the needs of a changing patient population.

Clinical Competence↗
PubMed2005

Randomized comparison between normothermic and hypothermic cardiopulmonary bypass in pediatric open-heart surgery.

BACKGROUND: The purpose of this study is to investigate the effect of cardiopulmonary bypass (CPB) temperature on myocardial reperfusion injury, oxidative stress, and inflammatory response in pediatric open heart surgery. METHODS: Fifty-nine children (median age 78 months; interquartile range, 39-130) undergoing correction of simple congenital heart defects were randomized to receive either hypothermic (28 degrees C) or normothermic (35-37 degrees C) CPB. Troponin I and 8-isoprostane, complement activation C3a, interleukin (IL) -6, -8, and -10, were measured preoperatively, on removal of the aortic cross clamp, 30 minutes, 6, and 24 hours postoperatively. RESULTS: Troponin I and 8-isoprostane were significantly raised, compared to baseline, in both groups, and remained high at 24 hours. Overall, troponin I and 8-isoprostane levels were 37% and 84% higher in the hypothermic than in the normothermic group, respectively (ratio 1.37, 95% CI 1.00 to 1.88, p = 0.053 and 1.84, 95% CI 1.22 to 2.78, p = 0.0045, respectively), and there was no evidence to suggest the treatment effect changed significantly over the time points measured (p = 0.63). Adjusting for aortic cross-clamp time reduced the effect of hypothermia on troponin (p = 0.18) but not on 8-isoprostane levels (p = 0.0028). The C3a, IL-6, and IL-8 release was similar in the two groups. The IL-10 release between the groups changed over time (p = 0.059) and examining differences at individual time points highlighted a statistically significant difference at the end of the cross-clamp time (p = 0.0079). CONCLUSIONS: Normothermic CPB is associated with reduced oxidative stress compared with hypothermic CPB, and similar myocardial reperfusion injury and whole body inflammatory response, in children undergoing open heart surgery. A larger study with clinical outcomes as primary end points is now warranted.

Biomarkers↗
PubMed2005

Incomplete revascularization during OPCAB surgery is associated with reduced mid-term event-free survival.

BACKGROUND: The aim of this study was to compare early and mid-term outcome in patients undergoing off-pump coronary artery bypass surgery who have had complete revascularizations and incomplete revascularizations (IRs). METHODS: Patient and operative data were collected prospectively for all patients who had off-pump coronary artery bypass surgery. Patients with multivessel disease were classified as having IR if the number of diseased coronary systems (left anterior descending coronary artery, circumflex and right coronary artery) exceeded the number of distal anastomoses. In-hospital outcomes, survival, and event-free survival were compared between patients with complete revascularization and IR using propensity scores to take account of differences in prognostic factors. RESULTS: There were 1,479 off-pump coronary artery bypass surgery patients between April 1996 and December 2002 (30% of all coronary artery bypass graft patients), and 16.0% (237 patients) had IRs. Patients with IRs tended to be older and were female, had more extensive disease, worse dyspnea, a higher Parsonnet score, poorer ejection fraction, congestive cardiac failure, asthma or chronic obstructive airways disease, and previous cardiac surgery. The adjusted hazard ratio for patient survival with IRs versus complete revascularizations was 1.56 (95% confidence interval, 1.19 to 2.06; p = 0.001). Analyses for multiple time periods confirmed that IRs had a significantly increased risk of death, but also that the risk disappeared after the first 4 to 6 months of follow-up (p < 0.0001). CONCLUSIONS: Compared with off-pump coronary artery bypass surgery patients with complete revascularizations, those with IRs have reduced survival, but only in the first 4 to 6 months after surgery. Patients' preoperative condition, rather than IR itself, may explain these findings because IRs should have mid-term as well as early effects.

Adolescent↗
PubMed2004

Basal metabolic state of hearts of patients with congenital heart disease: the effects of cyanosis, age, and pathology.

BACKGROUND: Experimental models have established numerous myocardial metabolic changes with chronic hypoxia and maturation. We conducted this study to specifically look at the effects of cyanosis, age, and pathology upon the basal metabolic state of the immature human heart. METHODS: One hundred and eighty-one pediatric patients (37 cyanotic, 144 acyanotic) undergoing open heart surgery were recruited. A myocardial biopsy was collected before ischemia and analyzed for adenine nucleotides, purines, and lactate. The effect of cyanosis was estimated by an analysis of age-matched pairs of children with either ventricular septal defects or tetralogy of Fallot, and by multiple regression modeling. The effects of age and pathology were estimated in acyanotic children also by multiple regression modeling (adjustments were made for baseline differences). RESULTS: The only effect of cyanosis was for lactate where the paired t test, and unadjusted and adjusted regression analyses were all consistent (ranging from 1.33 to 1.48 times higher in cyanotic than acyanotic children). The concentrations of adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) declined with age, whereas the ATP/ADP ratio increased; these associations remained significant even in the adjusted regression analysis. None of the effects of acyanotic pathology were highly significant (p < 0.01), implying that few important metabolic differences were attributable to pathology. CONCLUSIONS: Cyanosis and age are important factors that determine the basal metabolic state of the pediatric heart. Cyanotic patients have higher myocardial lactate concentrations, whereas young age is associated with lower ATP/ADP ratios and higher adenine nucleotide levels.

Adenine Nucleotides↗
PubMed2004

Increased airway mucins after cardiopulmonary bypass associated with postoperative respiratory complications in children.

OBJECTIVE: Airway mucins may play an important role in the mechanism of respiratory complications after cardiopulmonary bypass in infants and children. Our aim was to measure airway mucin levels before and after cardiopulmonary bypass and to determine whether changes in mucin levels were associated with the development of respiratory complications. METHODS: Airway glycoprotein and mucins (MUC5AC, MUC5B, and MUC2) in serial small-volume airway lavage samples from 39 young children who underwent cardiac operations with cardiopulmonary bypass were measured by slot-blot assay with specific antimucin peptide antibodies. The relationship between mucin changes and post-cardiopulmonary bypass respiratory complications was investigated. Airway lavage samples were also collected from 11 children before and after operation without cardiopulmonary bypass, and changes in mucin levels were compared with those in subjects who underwent cardiopulmonary bypass. Airway lavage sample DNA was also measured to investigate the relationship between mucin changes and lung injury. RESULTS: Glycoprotein, MUC5AC, and MUC5B levels were significantly increased after cardiopulmonary bypass (P <.001) whereas MUC2 level was not. Children with respiratory complications showed significantly higher glycoprotein and MUC5AC levels than did children without respiratory complications before and after cardiopulmonary bypass (P <.05). Increase of total mucin (MUC5AC, MUC5B, and MUC2) during cardiopulmonary bypass showed positive correlation with DNA increase during cardiopulmonary bypass (r = 0.73), PaCO(2) (r = 0.62) and alveolar-arterial oxygen difference (r = 0.55) immediately after cardiopulmonary bypass. Increase of total mucin was associated with postoperative respiratory complications and their severity. There were no significant changes detected in airway mucin during operations without cardiopulmonary bypass. CONCLUSIONS: Airway mucins were increased during cardiopulmonary bypass, and this increase was associated with markers of lung injury after cardiopulmonary bypass and with the development of postoperative respiratory complications.

Biomarkers↗
PubMed2004

Monitoring the performance of residents during training in off-pump coronary surgery.

OBJECTIVE: Control charts (eg, cumulative sum charts) plot changes in performance with time and can alert a surgeon to suboptimal performance. They were used to compare performance of off-pump coronary artery bypass surgery between a consultant and four resident surgeons and to compare performance of off-pump coronary artery bypass surgery and conventional coronary artery bypass grafting within surgeons. METHODS: Data were analyzed for consecutive patients undergoing coronary artery bypass grafting who were operated on by one consultant or one of four residents. Conversions were analyzed by intention to treat. Perioperative death or one or more of 10 adverse events constituted failure. Predicted risks of failure for individual patients were derived from the study population. Variable life-adjusted displays and risk-adjusted sequential probability ratio test charts were plotted. RESULTS: Data for 1372 patients were analyzed; 769 of the procedures were off-pump coronary artery bypass operations (56.0%). The consultant operated on 382 patients (293 off-pump, 76.7%), and the residents operated on 990 (474 off-pump, 47.9%). Patients operated on by residents tended to be older, more obese, more likely to require an urgent operation, and more likely to need a circumflex artery graft but less likely to have triple-vessel disease. There were 7 conversions (consultant 5, residents 2). The overall failure rate was 8.5% (9.2% for consultant's operations and 8.2% for residents' operations), including 10 deaths (0.7%). Predicted and observed risks of failure were similar for all five surgeons. After 100 off-pump coronary artery bypass operations, performance was the same or better for the residents as for the consultant. For all surgeons, performance was the same or better for off-pump as for conventional coronary artery bypass grafting. CONCLUSIONS: Off-pump coronary artery bypass surgery can be safely taught to cardiothoracic residents. Implementation of continuous performance monitoring for residents is practicable.

Cardiology↗
PubMed2003

Off-pump coronary artery bypass grafting: not a flash in the pan.

During the past decade, technical improvements have made off-pump coronary artery bypass operations a routine procedure. During this time, off-pump coronary artery bypass has been audited against conventional techniques by many observational, case-matched, and prospective randomized studies. There is evidence in the literature suggesting that off-pump coronary artery bypass operations reduce postoperative morbidity, organ dysfunction, and costs, without compromising midterm outcome compared with conventional coronary operations. The available evidence also supports the view that high-risk patients might benefit the most from revascularization on the beating heart. High quality follow-up data are still needed to assess the impact of off-pump coronary artery bypass operations on long-term clinical outcome.

Coronary Artery Bypass↗
PubMed2003

Myocardial protection with intermittent cold blood during aortic valve operation: antegrade versus retrograde delivery.

BACKGROUND: Intermittent antegrade cold blood cardioplegia is superior to warm blood cardioplegia in patients who have aortic valve operation. This study compared the cardioprotective efficacy of intermittent antegrade and retrograde cold blood cardioplegia with emphasis on metabolic stress in the left and right ventricles. METHODS: Thirty-nine patients who had elective aortic valve replacement were prospectively randomly selected to receive intermittent antegrade or retrograde cold blood cardioplegia. Left and right ventricular biopsies were collected 5 minutes after institution of cardiopulmonary bypass and 20 minutes after cross-clamp removal and were used to determine metabolic changes. Metabolites (adenine nucleotides, amino acids, and lactate) were measured using high-powered liquid chromatography and enzymatic techniques. Serial measurement of troponin I release was also used as a marker of myocardial injury. RESULTS: Preoperative characteristics were similar between groups. There was no in-hospital mortality, and no differences were observed in postoperative complications. Preischemic concentration of taurine was significantly higher in left ventricular biopsies, whereas adenosine triphosphate tended to be lower in the left ventricle. At reperfusion adenosine triphosphate levels were significantly lower than preischemic levels in right but not left ventricles irrespective of the route of delivery. The alanine-glutamate ratio was significantly elevated in both ventricles. Myocardial injury as assessed by troponin I release was also significantly increased in both groups. CONCLUSIONS: Retrograde and antegrade intermittent cold blood cardioplegic techniques are associated with suboptimal myocardial protection. Metabolic stress was more pronounced in the right than the left ventricle irrespective of the cardioplegic route of delivery used.

Adenine Nucleotides↗
PubMed2003

Radial versus right internal thoracic artery as a second arterial conduit for coronary surgery: early and midterm outcomes.

OBJECTIVE: We sought to compare early and midterm clinical outcomes in patients receiving a right internal thoracic artery or a radial artery as the second arterial conduit for myocardial revascularization. METHODS: Data prospectively collected for all patients who underwent coronary artery bypass surgery between April 1996 and May 2001 and who received both a left internal thoracic artery graft and either a right internal thoracic artery (n = 336) or a radial artery graft (n = 325) were analyzed. Patients in the radial artery group were older, with a greater body mass index, poorer ejection fraction, greater prevalence of diabetes, and higher New York Heart Association class than those in the right internal thoracic artery group. RESULTS: Odds ratios for perioperative myocardial infarction, atrial fibrillation, postoperative transfusion, and intensive care unit stay all showed a statistically significant benefit in the radial artery group compared with results in the right internal thoracic artery group (P <or=.05). Survival estimates at 18 months for patients who received right internal thoracic artery and radial artery grafts were 98.4% and 99.7%, respectively (hazard ratio, 0.25; 95% confidence interval, 0.06-1.10; P =.07). Estimates for survival free from any cardiac-related event or death in the right internal thoracic artery and radial artery groups were 92.3% and 97.8%, respectively (hazard ratio, 0.37; 95% confidence interval, 0.16-0.84; P =.02). A multivariate Cox regression model showed a stronger protective effect of a radial artery graft (hazard ratio, 0.25; 95% confidence interval, 0.12-0.51; P <.0001). CONCLUSION: Early and midterm outcomes of myocardial revascularization with 2 arterial grafts are better if the radial artery is used for the second graft rather than the right internal thoracic artery, assuming that the left internal thoracic artery is used for the first arterial graft.

Aged↗
PubMed2002

Magnesium-supplemented warm blood cardioplegia in patients undergoing coronary artery revascularization.

BACKGROUND: Although there is growing evidence to suggest that the administration of magnesium (Mg2+) to patients undergoing coronary artery bypass grafting (CABG) and to patients after myocardial infarction is beneficial, the addition of Mg2+ to cardioplegic solutions remains controversial. The aim of this study was to compare the effects of intermittent warm blood cardioplegia with and without Mg2+ supplementation on the early postoperative clinical outcomes in patients undergoing both elective or urgent CABG. METHODS: Four hundred patients undergoing CABG were prospectively randomized to receive either blood cardioplegia without Mg2+ (BC, n = 200) or supplemented with Mg2+ (BC-Mg2+, n = 200). Serial plasma Mg2+ concentrations were recorded at base line and postoperatively from days 1 to 4. RESULTS: Patient characteristics were similar and no significant differences were found in early mortality and morbidity in the two groups. Analysis of 178 patients undergoing urgent CABG for unstable symptoms (BC = 95, BC-Mg2+ = 83) demonstrated a significantly lower requirement for internal defibrillation and temporary epicardial pacing in the BC-Mg2+ group. Furthermore, there was a nearly twofold lower incidence of new postoperative atrial fibrillation in the BC-Mg2+ group compared with the BC group (19% versus 34%, p = 0.03). Postoperative plasma Mg2+ levels were consistently lower in those patients who developed new postoperative atrial fibrillation compared with those who did not (p = 0.05). CONCLUSIONS: The addition of Mg2+ to warm blood cardioplegia resulted in a lower incidence of intraoperative and postoperative arrhythmias in patients undergoing urgent CABG for unstable angina.

Aged↗
PubMed2002

Intracoronary shunts reduce transient intraoperative myocardial dysfunction during off-pump coronary operations.

BACKGROUND: This study investigated the hemodynamic changes in patients undergoing multiple vessel beating heart coronary revascularization in the presence or absence of an intracoronary shunt. METHODS: Forty patients were randomized to off-pump with a shunt (n = 20) or with the proximal coronary artery occluded by a soft snare (n = 20). Hemodynamic measurements were recorded at base line, during construction, and after completion of each distal anastomosis. RESULTS: Grafting of the left anterior descending coronary artery anastomosis was associated with a significant decrease in stroke volume, cardiac index, and mean arterial pressure, and an increase in pulmonary capillary wedge pressure and systemic vascular resistance in the snare but not in the shunt group. During grafting of the posterior descending coronary artery there was a marked decrease in stroke volume and cardiac index, and an increase in central venous pressure in both groups, and an increase in heart rate, mean pulmonary arterial pressure, pulmonary capillary wedge pressure, and systemic vascular resistance only in the snare group. The most extensive changes were observed during the circumflex coronary artery anastomosis with a reduction in stroke volume, cardiac index, and mean arterial pressure, and an increase in central venous pressure, pulmonary capillary wedge pressure, pulmonary arterial pressure, and systemic vascular resistance in both groups. In all settings, these changes were transient and recovered after the heart was returned to its anatomical position in the shunt group, whereas stroke volume and cardiac index remained reduced, and systemic vascular resistance was elevated in all settings in the snare group. CONCLUSIONS: Stabilization of the left anterior descending coronary artery to perform the anastomosis resulted in temporary hemodynamic changes, which are prevented by the use of an intracoronary shunt. The hemodynamic deterioration during the construction of the posterior descending coronary artery and circumflex coronary artery anastomoses is transient in the shunt group, whereas the snaring technique is associated with an impairment of early functional recovery.

Aged↗