Predictors of early and mid-term results in contemporary aortic valve replacement for aortic stenosis

BACKGROUND

The purpose of this study was to evaluate clinical risk factors and assess the impact of the Society of Thoracic Surgeons (STS) scores on outcomes after contemporary aortic valve replacement (AVR) for aortic stenosis (AS).

METHODS

We retrospectively analyzed the data from 209 consecutive patients with AS (mean 69 ± 9 years) who underwent AVR. The outcomes measured included operative mortality, postoperative complications, postoperative prolonged length of stay (PLOS), discharge to nonhome location, and mid-term mortality.

RESULTS

Operative mortality was 3.8%, and five-year survival was 88.6 ± 2.8%. Multivariable analysis revealed preoperative New York Heart Association (NYHA) class as a significant predictor of both operative mortality (p = 0.03; odds ratio [OR]: 8.5) and mid-term mortality (p = 0.02; OR: 10.5). NYHA class also emerged as an independent predictor for postoperative complications (p = 0.002; OR: 5.8) and PLOS (p = 0.01; OR: 2.5). Other preoperative independent predictors included dialysis for PLOS (p = 0.04; OR: 2.9), age (p = 0.03; OR: 1.1), and left ventricular ejection fraction (EF; p = 0.03; OR: 0.9) for nonhome discharge, and EF for mid-term mortality (p = 0.01; OR: 0.9). The mean STS-PROM (predicted risk of mortality) was 4.6% ± 6.1%, and thus, the observed-to-expected (O/E) ratio of operative mortality in our series was 0.82.

CONCLUSIONS

Advanced NYHA class, older age, dialysis, and lower EF are significant independent preoperative risk factors for early and mid-term results of AVR for AS. Consideration of these predictors should be used to identify high-risk patients requiring AVR for AS.

Phosphorylation status of heat shock protein 27 regulates the interleukin-1β-induced interleukin-6 synthesis in C6 glioma cells

Heat shock protein 27 (HSP27), a low-molecular-weight HSP, is recognized as a molecular chaperone. In response to various stimuli, HSP27 expression is induced in the CNS. However, the exact roles of HSP27 in the CNS have not yet been clarified. It has been reported that interleukin (IL)-1β stimulates IL-6 synthesis in C6 glioma cells. In the present study, we investigated the role of HSP27 in the IL-1β-induced IL-6 synthesis in C6 cells. IL-1β alone did not affect the levels of HSP27. The IL-1β-induced IL-6 release in HSP27-downregulated C6 cells were enhanced compared with those in control siRNA-transfected cells. On the other hand, the IL-1β-induced IL-6 release was significantly enhanced in C6 cells transfected with HSP27 than those in control cells in time- and dose-dependent manner. The IL-1β-induced IL-6 release and the mRNA expression were markedly suppressed in C6 cells transfected with phosphorylated HSP27, while those in the cells transfected with unphosphorylated HSP27 were enhanced. In conclusion, these results strongly suggest that phosphorylated status of HSP27 has a switching role in the IL-1β-induced IL-6 synthesis in C6 glioma cells.

[Off-pump coronary artery bypass grafting as standard operation; surgical strategies and results]

We report the clinical results of 799 cases of isolated coronary artery bypass grafting (CABG) performed during the recent 5 years. We performed off-pump CABG (OPCAB) as standard operation, in which arterial grafts were mainly used. The mean number of distal anastomoses was 3.6 +/- 1.4 per patient Four hundred and fifty-five cases (57.0%) were done only with arterial grafts. Bilateral internal thoracic arteries were used in 326 cases. The mean number of saphenous vein grafts was 1.6 +/- 0.8 per patient. Continuous hemodiafiltraion (CHDF) was performed in 22 cases (2.8%) postoperatively. Among the OPCAB cases, 10 cases (1.3%) were converted to on-pump CABG. There were 7 cases (0.9%) of hospital death. The mean length of postoperative hospital stay was 10.2 +/- 5.3 days. The ratio of the patients with left main trunk disease and that of the patients who required postoperative CHDF increased year by year. The mean length of postoperative hospital stay decreased every year, and the reduced length was 2.7 days in the 5 years (8.7+/- 3.6 days in 2007). It is expected that patients who have severe calcified lesions or who are on hemodialysis may increase in the near future. In such cases, CABG rather than percutaneous catheter intervention may be suitable for revascularization. Therefore, not only appropriate choice of treatment strategies, but also accurate surgical techniques may become more importance.

Prognostic effects of calcium channel blockers on cardiac events, stroke and end-stage renal disease in patients with angina pectoris. Retrospective comparative study of benidipine, diltiazem and nifedipine

BACKGROUND AND AIM

Calcium channel blockers (CCBs) have been reported to reduce the incidence of stroke in hypertensive patients. CCBs are also commonly used to treat patients with angina pectoris (AP). However, there are very few reports on their effects on cardiovascular events, including stroke and end-stage renal disease (ESRD), in patients with AP. This study was designed to assess the differences among CCBs regarding the occurrence of cardiovascular events in patients with AP.

METHODS

Clinical records of 226 patients with AP who had received treatment with CCBs in hospital from January 1, 1993 to December 31, 2006 were reviwed. The influence of patient characteristics and medication on the occurrence of cardiovascular events was evaluated (median follow-up period: 4.4 years). Of these 226 patients, 155 were treated with benldipine (CAS 91599-74-5), 36 with diltiazem (CAS 33286-22-5), and 35 were treated with nifedipine (CAS 21629-25-4).

RESULTS

Cox proportional hazard regression analysis showed that benidipine was the only CCB that significantly reduced the occurrence of cardiovascular events (HR = 0.39, p < 0.05). Benidipine treatment was associated with higher cardiovascular- and cardiac event-free rates than diltiazem treatment, and higher stroke- and ESRD-free rates than nifedipine.

CONCLUSION

This study demonstrated that benidipine prevents the occurrence of cardiovascular events in patients with AP, suggesting that benidipine contributes to a favorable long-term prognosis of such patients.

Effects of ifenprodil on voltage-gated tetrodotoxin-resistant Na+ channels in rat sensory neurons

BACKGROUND AND OBJECTIVE

To examine a possible mechanism for the antinociceptive action of the N-methyl-D-aspartate receptor antagonist ifenprodil, we compared its effects with those of ketamine on tetrodotoxin-resistant Na+ channels in rat dorsal root ganglion neurons, which play an important role in the nociceptive pain pathway.

METHODS

Experiments were performed on dorsal root ganglion neurons from Sprague-Dawley rats, recordings of whole-cell membrane currents being made using patch-clamp technique.

RESULTS

Both drugs blocked tetrodotoxin-resistant Na+ currents dose dependently, their half-maximal inhibitory concentrations being 145+/-12.1 micromol (ketamine) and 2.6+/-0.95 micromol (ifenprodil). Ifenprodil shifted the inactivation curve for tetrodotoxin-resistant Na+ channels in the hyperpolarizing direction and shifted the activation curve in the depolarizing direction. Use-dependent blockade of tetrodotoxin-resistant Na+ channels was more marked with ifenprodil than with ketamine. When paired with lidocaine, these drugs produced similar additive inhibitions of tetrodotoxin-resistant Na+ channel activity.

CONCLUSIONS

The observed suppressive effects on tetrodotoxin-resistant Na+ channel activity may, at least in part, underlie the antinociceptive effects of these N-methyl-D-aspartate receptor antagonists.

Effects of alpha2-adrenoceptor agonists on tetrodotoxin-resistant Na+ channels in rat dorsal root ganglion neurons

BACKGROUND AND OBJECTIVE

When intrathecally or epidurally administered, alpha2-adrenoceptor agonists produce potent antinociception by affecting the activity of primary afferent fibres and spinal cord neurons. Recent reports have indicated that in dorsal root ganglion neurons, tetrodotoxin-resistant Na+ channels play important roles in the conduction of nociceptive sensation. We therefore investigated the effects of alpha2-adrenoceptor agonists on tetrodotoxin-resistant Na+ currents.

METHODS

Using the whole-cell patch-clamp technique, we recorded tetrodotoxin-resistant Na+ currents from rat dorsal root ganglion neurons.

RESULTS

Both clonidine and dexmedetomidine reduced the peak amplitude of the tetrodotoxin-resistant Na+ current concentration- and use-dependently. The concentration required for a half-maximal effect was significantly lower for dexmedetomidine (58.0 +/- 10.2 micromol) than for clonidine (257.2 +/- 30.9 micromol) at holding potential -70 mV. The current inhibitions induced by these agonists were not prevented by 1 micromol yohimbine, an alpha2-adrenoceptor antagonist. Both clonidine and dexmedetomidine shifted the inactivation curve for the tetrodotoxin-resistant Na+ current in the hyperpolarizing direction. The combinations clonidine with lidocaine and dexmedetomidine with lidocaine produced an additive blockade-type interaction on the tetrodotoxin-resistant Na+ current.

CONCLUSIONS

The results suggest that a direct inhibition of tetrodotoxin-resistant Na+ channels may contribute to the antinociceptive effects of clonidine and dexmedetomidine when used as additives to regional anaesthesia.

Epidural morphine injection after combined spinal and epidural anaesthesia

BACKGROUND AND OBJECTIVE

Although combined spinal and epidural anaesthesia is efficient and easy to perform, the technique can be a double-edged sword having the potential risk that an increased flux of drugs across the meninges through the hole made in it may lead to severe adverse effects. The aim was to compare the incidence of adverse events when an epidural injection of morphine was given after combined spinal and epidural anaesthesia or after epidural anaesthesia.

METHODS

Fifteen patients had an epidural catheter inserted at the L2-3 interspace, and then a spinal block administered via the L3-4 interspace. Another 15 patients only had an epidural catheter inserted. After the onset of spinal or epidural anaesthesia had been confirmed, morphine 2 mg was injected into the epidural space, and a continuous epidural infusion of morphine was started. At the end of the operation and at 4, 8 and 12 h after the administration of epidural morphine and on the next day, the following variables were examined: blood pressure, heart rate, respiratory rate, arterial blood-gas analysis, visual analogue scale pain scores, nausea/vomiting scores, and pruritus scores.

RESULTS

In the study population, the epidural injection of morphine was not associated with a significantly higher incidence of adverse events when given after spinal anaesthesia than after epidural anaesthesia.

CONCLUSIONS

The adverse effects associated with epidural morphine given after spinal anaesthesia did not increase significantly when a 27-G Whitacre needle was used. Thus, the morphine flux through the meningeal hole into the cerebrospinal fluid was trivial.

Modified nasal cannula for simultaneous oxygen delivery and end-tidal CO2 monitoring during spontaneous breathing

BACKGROUND AND OBJECTIVES

Supplemental oxygen is commonly given via nasal cannulae in spontaneously breathing patients. Our modified nasal cannula with a clamp between the nasal prongs can provide O2 via one nostril and CO2 can be sampled through the other one. We have studied whether this cannula can provide oxygenation similar to a standard cannula without affecting end-tidal CO2 monitoring.

METHODS

Eighty-six patients were studied during spinal anaesthesia and sedation. In 15 patients, arterial blood was sampled while O2 was delivered at flow rates of 0, 2 and 4 L min(-1), with or without clamping between the prongs of our modified nasal cannula. In the remaining 71 patients, arterial O2 was measured while using our modified nasal cannula with the clamp applied. End-tidal CO2 was recorded on a capnograph and the correlation between end-tidal and arterial values with our modified nasal cannula was investigated.

RESULTS

No end-tidal CO2 waveforms were found with oxygen flow greater than 2L min(-1) without clamping between the prongs. With clamping there was a significant correlation (r = 0.83) between arterial and end-tidal CO2. A Bland-Altman analysis revealed a bias of 0.49 kPa with precision of +/-0.76 kPa. Arterial oxygenation was not affected by our modified nasal prongs with clamp as compared to the standard cannula.

CONCLUSION

Our modified nasal cannula can provide continuous monitoring of end-tidal CO2 without affecting oxygen delivery in sedated, spontaneously breathing patients.

Epidural oxycodone or morphine following gynaecological surgery †

BACKGROUND

The analgesic action of oxycodone is of rapid onset, in contrast to morphine, and is mediated by kappa-opioid receptors of the spinal cord. We compared analgesia and side-effects of epidural oxycodone with those of morphine after gynaecological surgery.

METHODS

We studied prospectively in 75 women in a double-blind, randomized manner: epidural morphine 6 mg day(-1) (n=25), epidural oxycodone 6 mg day(-1) (n=25) and epidural oxycodone 12 mg day(-1) (n=25). All patients underwent gynaecological surgery under general (isoflurane and nitrous oxide) and epidural anaesthesia. Visual analogue scale (VAS) pain scores at rest and on coughing, verbal descriptive scale (VDS) satisfaction scores, sedation scores, pruritus scores and nausea/vomiting scores were recorded for 3 days after surgery.

RESULTS

VAS pain scores at rest in patients who received oxycodone 6 mg day(-1) were higher than in patients who received morphine 6 mg day(-1) at 6 h and on the first postoperative day and were significantly higher than in patients who received oxycodone 12 mg day(-1) on the first postoperative day. Scores for nausea, vomiting and pruritus in patients who received oxycodone 6 mg day(-1) and 12 mg day(-1) were lower than those in patients who received morphine. No significant differences were seen in VAS at cough and VDS satisfaction scores between the three groups.

CONCLUSION

Epidural oxycodone was as effective as morphine at the doses investigated, with fewer side-effects.

Skeletonized Gastroepiploic Artery for Off-Pump Coronary Artery Bypass Grafting

BACKGROUND

Skeletonized arterial grafting may reduce the risk of graft spasm and may improve graft patency. Previously we reported a pilot study of skeletonized gastroepiploic artery (GEA) grafting with favorable results. Skeletonized GEA harvesting with an ultrasonic scalpel has now become our routine procedure. In this report, we compare the early clinical outcomes of skeletonized versus pedicled GEA grafting to assess the safety and benefit of use of skeletonized GEA in coronary artery bypass grafting.

METHODS

Between July 2002 and October 2003, the GEA was used as a conduit for isolated off-pump coronary artery bypass grafting in 105 patients. Of these, 21 patients (group P) received pedicled GEA and 59 patients (group S) received skeletonized GEA grafts (excluding 25 patients whose results were reported in the pilot study). The perioperative and early follow-up data were prospectively collected and compared.

RESULTS

No graft injury was found in either group. The preoperative characteristics were similar in the two groups except that group S had a smaller body surface area (1.64 +/- 0.16 m 2 in group S versus 1.73 +/- 0.16 m 2 in group P, P <.05) and a significant number of patients with diabetes (36/59, 61.0% versus 7/21, 33.3%, P <.05). The number of distal anastomoses was 4.3 < 1.0 versus 3.9 +/- 0.9 ( P = not significant [NS]). An in situ GEA composite graft was constructed in 8 (13.6%) of the patients in group S and none of the patients in group P ( P = NS). There was one hospital death due to infection in group S. Otherwise, there were no cases of low output syndrome or postoperative myocardial infarction in either group. During early postoperative follow-up, no angina recurrence or myocardial infarction was found.

CONCLUSION

The GEA can be skeletonized safely with an ultrasonic scalpel. Skeletonization enables a wider variety of choices in the use of GEA grafting.

Venous coronary artery bypass grafting: late results of a 15-year actuarial follow-up in 486 patients

PURPOSE

The aim of this study was to clarify the long-term results of venous coronary artery bypass grafting in Japanese patients.

METHODS

The study population included 492 patients who underwent venous coronary artery bypass procedures at the Department of Cardiothoracic Surgery of Juntendo University from January 1984 to December 1989. The great majority of patients, 420 of 492 (85.4%), were males, and the mean patient age was 61.1 years (range: 32-82 years). The disease conditions included single-vessel disease in 32 patients (6.5%), double-vessel disease in 111 patients (22.6%), triple-vessel disease in 251 patients (51.2%), and 50% or more stenosis of the left main coronary artery in 98 patients (19.9%). A mean of 2.4 grafts was used per patient.

RESULTS

The 15-year survival rate was 57.7%. The 15-year actuarial cardiac survival and cardiac event-free survival were 81.3% and 51.3%, respectively. The 15-year actuarial freedom from reoperation and myocardial infarction were 87.5% and 92.1%, respectively. Of 192 patients who died during the follow-up period, 62 deaths were due to cardiac causes (32.3%), 43 were due to malignant neoplasms (22.4%), and 25 were due to cerebral vascular accidents (13.0%).

CONCLUSION

The prognosis of Japanese patients undergoing coronary artery bypass grafting may therefore be more favorable than that of Western patients. In addition, diabetes mellitus was an independent risk factor for both cardiac death and cardiac events.

Anesthesia-related mortality and morbidity over a 5-year period in 2,363,038 patients in Japan

BACKGROUND

Statistical data of mortality and morbidity related to anesthesia have not been reported in Japan since World War II. The need to comprehensively examine the events of cardiac arrest as well as mortality prompted the first national study in Japan.

METHODS

Confidential questionnaires were sent to all Japan Society of Anesthesiologists Certified Training Hospitals every year from 1994 through 1998. Collected data were analyzed for incidence of cardiac arrest and other critical events during anesthesia and surgery, and their outcomes within 7 postoperative days. The principal causes of the critical incidents were also analyzed.

RESULTS

With an average response rate of 39.9%, a total of 2,363,038 cases were documented over 5 years. The average incidence per year of cardiac arrest during surgery due to all etiologies and that totally attributable to anesthesia was 7.12 [95%CI: 6.30,7.94] and 1.00 [0.88, 1.12]) per 10,000 cases, respectively. The average mortality per year in the operating room or within 7 postoperative days due to all etiologies and that totally attributable to anesthesia was 7.18 [6.22, 8.13] and 0.21 [0.15, 0.27] per 10,000 cases, respectively. The two principal causes of cardiac arrest during anesthesia and surgery due to all etiologies were massive hemorrhage (31.9%) and surgery (30.2%), and those totally attributable to anesthesia were drug overdose or selection error (15.3%) and serious arrhythmia (13.9%). Preventable human errors caused 53.2% of cardiac arrest and 22.2% of deaths in the operating room totally attributable to anesthesia.

CONCLUSIONS

The rates in Japan of cardiac arrest and death during anesthesia and surgery due to all etiologies as well as those totally attributable to anesthesia are comparable to those of other developed countries.

Changes in calcitonin gene-related peptide, atrial natriuretic peptide and brain natriuretic peptide in patients undergoing coronary artery bypass grafting

The initiation of cardiopulmonary bypass creates significant derangements in cardiovascular volume status and both endocrine and autonomic nervous system function. To examine whether such derangements might differ in patients with different pre-operative physical status scores, we measured the plasma concentrations of calcitonin gene-related peptide, atrial natriuretic peptide and brain natriuretic peptide, catecholamines and antidiuretic hormone, as well as haemodynamic variables, during and after cardiopulmonary bypass in 27 consecutive patients undergoing coronary artery bypass grafting. The pre-operative levels of atrial natriuretic peptide and brain natriuretic peptide differed significantly between ASA II patients and III and IV patients [mean (SD) brain natriuretic peptide levels = 14 (8.2) vs. 129 (51) pg.ml-1]. Plasma calcitonin gene-related peptide increased significantly in both groups after the initiation of cardiopulmonary bypass, and remained increased throughout cardiopulmonary bypass. The changes in plasma epinephrine, norepinephrine and antidiuretic hormone were similar to those reported previously. The changes in plasma calcitonin gene-related peptide, atrial natriuretic peptide and brain natriuretic peptide did not correlate with any changes in haemodynamic variables before or after cardiopulmonary bypass. Measurement of plasma brain natriuretic peptide might usefully be included in the pre-operative evaluation of patients with cardiac disease.

Metal allergy to stainless steel wire after coronary artery bypass grafting

To our knowledge, this is the first reported case of a manganese metal allergy to stainless steel wire. A 51-year-old man suffered from a refractory pruritic erythematous wheal after the insertion of a stainless steel wire. The patch test showed strong reactions to manganese, one of the constituents of stainless steel wire. After the removal of all stainless steel wires, the symptoms were much improved, except for mild pruritus on his face.

Off-pump coronary artery bypass grafting in a patient with liver cirrhosis

We report a case of unstable angina pectoris and alcohol-related Child-Pugh class B cirrhosis. The patient was a 60-year-old man who was admitted to hospital with chest pain. He had previously been diagnosed to have Child B cirrhosis due to alcoholic liver dysfunction at 58 years of age. He also had experienced ruptured esophageal varices, moderate ascites, and hyperammonemia. We performed percutaneous catheter intervention; however, he developed re-stenosis in the right coronary artery, and progression in the disease in other coronary arteries. We then performed coronary artery bypass grafting on the beating heart without cardiopulmonary bypass. He was discharged on the 13th postoperative day without any complications. This case demonstrated that off-pump coronary artery bypass grafting was safe for such a patient.