Risk factors associated with atrial fibrillation after noncardiac thoracic surgery: analysis of 2588 patients

OBJECTIVE: The purpose of this study was to identify risk factors associated with the onset of atrial fibrillation after thoracic surgery to allow more targeted interventions in patients with the highest risk. METHODS: A comprehensive prospective database was used to identify patients undergoing major thoracic surgery from January 1, 1998, through December 31, 2002. Data collection was performed at point of contact: at preoperative evaluation, the time of the operation, discharge, and postoperative visits. All patients undergoing resection of a lung, the esophagus, the chest wall, or a mediastinal mass were included in this study. Univariate and multivariate analyses of factors associated with the development of atrial fibrillation were analyzed. RESULTS: There were 2588 patients who met the inclusion criteria. The overall incidence of atrial fibrillation was 12.3% (n = 319). Categories of disease were primary lung cancer, pulmonary metastasis, esophageal cancer, intrathoracic metastasis, benign lung disease, other mediastinal tumors, mesothelioma, chest wall tumors, benign esophagus, and "other." Patients with atrial fibrillation had increased mean lengths of hospital stay, mortality rates, and mean hospital charges. Univariate analysis evaluated age, sex, disease category, comorbidities, preoperative therapy, and procedure, and significant variables were entered into the multivariate analysis. Significant variables (relative risk; 95% confidence interval) in the multivariate analysis were male sex (1.72; 1.29-2.28), age 50 to 59 years (1.70; 1.01-2.88), age 60 to 69 years (4.49; 2.79-7.22), age 70 years or greater (5.30; 3.28-8.59), history of congestive heart failure (2.51; 1.06-6.24), history of arrhythmias (1.92; 1.22-3.02), history of peripheral vascular disease (1.65; 0.93-2.92), resection of mediastinal tumor or thymectomy (2.36; 0.95-5.88), lobectomy (3.89; 2.19-6.91), bilobectomy (7.16; 3.02-16.96), pneumonectomy (8.91; 4.59-17.28), esophagectomy (2.95; 1.55-5.62), and intraoperative transfusions (1.39; 0.98-1.98). CONCLUSIONS: The significant variables identified by means of multivariate analysis were associated with the occurrence of atrial fibrillation. Preventive therapies in selected populations might reduce the incidence of atrial fibrillation.     

Potentially modifiable risk factors for atrial fibrillation following lung resection surgery: a retrospective cohort study

Atrial fibrillation is the most frequent arrhythmia after thoracic surgery and is associated with increased hospital costs, morbidity and mortality. In this study, we aimed to identify potentially modifiable risk factors for postoperative atrial fibrillation following lung resection surgery and to suggest possible measures to reduce risk. We retrospectively reviewed the medical records of 4731 patients who underwent lobectomy or more major lung resection over a 6‐year period. Patients who developed atrial fibrillation postoperatively and required treatment were included in the postoperative atrial fibrillation group, while the remaining patients were assigned to the non‐postoperative atrial fibrillation group. Risk factors for postoperative atrial fibrillation were analysed by multivariate analysis and propensity score matching. Overall, 12% of patients developed postoperative atrial fibrillation. Potentially modifiable risk factors for postoperative atrial fibrillation were excessive alcohol consumption (odds ratio (OR) = 1.48, 95% CI 1.08–2.02, p = 0.0140), red cell transfusion (2.70(2.13–3.43), p < 0.0001), use of inotropes (1.81(1.42–2.31), p < 0.0001) and open (vs. thoracoscopic) surgery (1.59(1.23–2.05), p < 0.0001). Compared with inotrope use, vasopressor administration was not related to postoperative atrial fibrillation. Use of steroids or thoracic epidural anaesthesia did not reduce the incidence of postoperative atrial fibrillation. We conclude that high alcohol consumption, red cell transfusion, use of inotropes and open surgery are potentially modifiable risk factors for postoperative atrial fibrillation. Pre‐operative alcohol consumption needs to be addressed. Avoiding red cell transfusion and performing lung resection via video‐assisted thoracoscopic surgery may reduce the incidence of postoperative atrial fibrillation and the administration of vasopressors rather than inotropes is preferred.     

Can local infiltration of lidocaine reduce the postoperative atrial fibrillation rate in patients undergoing lobectomy for lung cancer?

Abstract

Background: Postoperative atrial fibrillation (POAF) occurs frequently after lung cancer surgery. Unfortunately, owing to the multifactorial etiology of POAF, no single drug or intervention can prevent POAF in all cases. The effects of local interventions after lung cancer surgery are unknown. This study investigated the effects of local infiltration of an anesthetic (lidocaine) on the post-lobectomy POAF rate.

Methods: This non-randomized study included 81 patients who underwent lobectomy for lung cancer. Patients were divided into a lidocaine-infiltration group comprising patients who received lidocaine infiltration around the pulmonary veins and a no-intervention group. Patients were monitored for the development of POAF during hospitalization. Pre- and postoperative demographic and clinical data were analyzed.

Results: AF occurred in 3 (7.5%) of 40 patients in the lidocaine-infiltration group and in 10 (24.39%) of 41 patients in the standard surgical resection group. Overall, it was observed that intraoperative lidocaine infiltration resulted in a lower POAF rate (p?<?.05).

Conclusion: Local infiltration of lidocaine around the pulmonary veins in patients undergoing lobectomy for lung cancer was associated with a lower incidence of POAF, which is attributable to the local anesthetic and autonomic effects of lidocaine.     

Prophylaxis of atrial fibrillation after noncardiac thoracic surgery

Atrial fibrillation (AF) occurs commonly after noncardiac thoracic surgery, including lobectomy, pneumonectomy and esophagectomy. While not as extensively investigated as AF following cardiac surgery, some strategies for prophylaxis of AF after noncardiac thoracic surgery have been studied. Evidence from prospective, randomized controlled studies supports the use of beta-blockers, diltiazem, amiodarone or magnesium for prevention of AF after pulmonary resection. Limited evidence supports the efficacy of intravenous amiodarone for prevention of AF after esophagectomy. Further study is necessary to determine the safest and most effective methods of prophylaxis of AF after noncardiac thoracic surgery, and to identify patients most likely to benefit from AF prophylaxis.     

肺及部分左心房切除术治疗中心型肺癌

为探讨肺及部分左心房切除术在治疗侵及左心房的ＩＩｂ期肺癌的效果。对１９８３年２月至１９９４年１０月期间诊断为侵及左心房的ＩＩＩｂ期肺癌病人分为手术组２６例、探查组１４例。两组于围术期均行强化化疗和术后放、化疗。结果本组无手术死亡，探查组生存２～７个月，平均１３４天；切除组除５例术后１０～５８个月死于癌转移外，余２１例无癌生存６～８５个月。作者认为，肺叶或全肺切除并部分左心房切除能明显延长侵及左心房的ＩＩｂ期肺癌的生存时间。     

Atrial fibrillation after surgery of the lung: clinical analysis of risk factors

Objective: The aim of this study was to determine which of the clinical parameters are the most valuable in predicting postoperative atrial fibrillation after lung surgery. Materials and methods: Retrospective analysis was carried out on 298 patients after pulmonary resection necessitated mainly by lung cancer. The following parameters were investigated: age and sex, disturbances of cardiac rhythm, history of ischemic heart disease, diabetes and atherosclerosis, NYHA classification and type of surgical procedure. In addition, the duration of surgery, variations in oxygen saturation, changes in systemic blood pressure and heart-rate were noted intraoperatively. Statistical analysis was performed using Fisher's exact test. Results and conclusions: Atrial fibrillation occurred in 25 cases (8.4%) and more frequently after pneumonectomy (24%). Other factors contributing to atrial fibrillation after lung surgery were: history of ischemic heart disease, congestive heart failure, intraoperative cardiac arrest and the need for rethoracotomy.     

Atrial reduction plasty Cox maze procedure: extended indications for atrial fibrillation surgery

BACKGROUND: The Cox maze procedure yields good results for atrial fibrillation (AF). However, patients with predictors of failure-chronic long-standing AF, low amplitude fibrillatory waves, and large left atriums-are generally thought not to benefit from a maze procedure. We report an aggressive approach for these patients, utilizing biatrial reduction plasty concomitantly with the Cox maze procedure for AF. METHODS: A complete Cox maze procedure utilizing supplemental RF ablation was performed in 36 patients. All underwent resection of both atrial appendages and biatrial reduction plasty encompassing resection of the left atrial posterior wall from left to right pulmonary veins and from inferior pulmonary veins to the mitral annulus, as well as removal of the right atrial lateral wall. Mitral or tricuspid valve repair, or both, was performed on 32 patients. RESULTS: These patients had a mean AF duration of 45 +/- 89 months. Their preoperative left atria measured 66 +/- 16 mm, with mean AF waves of 0.74 +/- 0.3 mm. Mean preoperative New York Heart Association class was 2.7 +/- 0.7 and left ventricular ejection fraction was 48 +/- 9. Cross clamp and bypass times were 91 +/- 35 minutes and 124 +/- 33 minutes, respectively. The average posterior left atrial tissue resected was 5.4 x 2.1 cm, and mean resected atrial weight was 10.3 +/- 2 g. There were no deaths and length of stay was 5.5 +/- 2 days. At a follow-up time of 19 +/- 16 months, 32 of the 36 patients were in normal sinus rhythm and New York Heart Association class I. CONCLUSIONS: Aggressive biatrial reduction plasty Cox maze procedure was effective in 89% of these "low success" AF patients. This simple procedure can extend utilization of the Cox maze procedure to more patients with chronic AF.     

Operative management and outcomes of traumatic lung resection

BACKGROUND: To analyze the presentation, injury patterns, and outcomes among a large cohort of patients requiring lung resection for trauma, and to compare outcomes stratified by the extent of resection. STUDY DESIGN: Review of all adult patients undergoing lung resections in the National Trauma Data Bank. Patients were categorized by extent of lung resection; wedge resection, lobectomy, or pneumonectomy. Patient factors, injury data, and outcomes were compared between groups using univariate and multivariable analysis for the entire sample, and after excluding patients with severe associated injuries. RESULTS: There were 669 patients who had a lung resection after trauma identified for an overall prevalence of 0.08%, with 325 undergoing wedge resection (49%), 244 had a lobectomy (36%), and 100 underwent complete pneumonectomy (15%). Blunt mechanism was associated with worse outcomes in terms of prolonged hospital stay, complications, disability, and a trend toward higher mortality (38% versus 30%, p = 0.07). Patients undergoing pneumonectomy had a higher mortality (62%) and more complications (48%) compared with patients undergoing lobectomy (35% mortality, 33% complications) and wedge resection (22% and 8%, all p < 0.05). After excluding patients with severe associated injuries (head, abdomen, heart, great vessels), there were 535 patients with "isolated" lung injury. There was again a stepwise increase in mortality by extent of resection, 19% for wedge resection, 27% for lobectomy, and 53% for pneumonectomy. Extent of lung resection remained an independent predictor of mortality for both the entire sample and for patients with isolated lung injury. CONCLUSIONS: Lung resection is infrequently required for traumatic injury, but carries substantial associated morbidity and mortality. The extent of lung resection is an independent predictor of hospital mortality, even after exclusion of patients with severe associated injuries. The worst outcomes were seen after complete pneumonectomy.     

Cardiac arrhythmias following pneumonectomy

A series of 260 patients who underwent pneumonectomy for cancer of the lung was analysed for post-operative arrhythmias. Of these patients 28% developed such arrhythmias, usually in the form of atrial fibrillation, on the first to third post-operative day, rapidly yielding to fast-acting digitalis preparations. Possible aetiological factors were investigated, but no single cause was demonstrable. The indication for pre-operative digitalization, if any, is discussed.     

Atrial fibrillation complicating lung cancer resection

OBJECTIVE: To (1) characterize atrial fibrillation complicating lung cancer resection, (2) evaluate its temporal relationship to other postoperative complications, and (3) assess its economics. METHODS: From January 1998 to August 2002, 604 patients underwent anatomic lung cancer resection. Atrial fibrillation prevalence, onset, and temporal associations with other postoperative complications were determined. Propensity matching was used to assess economics. RESULTS: Atrial fibrillation occurred in 113 patients (19%), peaking on postoperative day 2. Older age, male gender, heart failure, clamshell incision, and right pneumonectomy were risk factors (P < .01). Although atrial fibrillation was solitary in 75 patients (66%), other postoperative complications occurred in 38. Respiratory and infectious complications were temporally linked with atrial fibrillation onset. In 91 propensity-matched pairs, patients developing atrial fibrillation had more other postoperative complications (30% vs. 9%, P < .0004), had longer postoperative stays (median 8 vs 5 days, P < .0001), incurred higher costs (cost ratio 1.8, 68% confidence limits 1.6-2.1), and had higher in-hospital mortality (8% vs 0%, P = .01). Even when atrial fibrillation was a solitary complication, hospital stay was longer (median 7 vs 5 days, P < .0001), and cost was higher (cost ratio 1.5, 68% confidence limits 1.2-1.6). CONCLUSION: Atrial fibrillation occurs in 1 in 5 patients after lung cancer resection, with peak onset on postoperative day 2. Risk factors are both patient and procedure related, and atrial fibrillation may herald other serious complications. Although often solitary, atrial fibrillation is associated with longer hospital stay and higher cost. It therefore requires prompt treatment and should stimulate investigation for other problems.     

Evaluation of T factor, surgical method, and prognostic factors in central type lung cancer

OBJECTIVE: We report our experience in the diagnosis and surgical treatment of central type lung cancer (CTLC) and discuss the prognostic significance of clinicopathological factors including the T factor. METHODS: Subjects were 151 patients with CTLC undergoing surgery from 1984 to 1999. Surgical procedures include lobectomy in 111, pneumonectomy in 35, and segmentectomy in 5. Bronchoplasty was done in 44, including sleeve lobectomy in 33, carinal resection in 8, and bronchoplasty without resection of pulmonary parenchyma in 3. Data on CTLC was compared to that on peripheral lung cancer during the same period. RESULTS: Compared to peripheral tumors, central lung tumors showed a higher ratio in male gender, pN1 in pN factors, squamous cell carcinoma in histology, and pneumonectomy and bronchoplasty in surgery. No statistical differences were seen between groups in surgical outcome, mean age, distribution pattern in pT factors, and extended surgery. The positive predictive cT factor has improved. No significant difference was seen in 5-year survival based on 8 factors--period, cT factors, tumor histology, bronchoplasty, extended surgery, cellular atypia, additional chemotherapy, and radiotherapy. Five-year survival differed significantly for 12 other factors--pT, cN, and pN factors; surgical method; number of resected organs in extended surgery; curability (complete/incomplete); tumor size; N1 and N2 station metastasis; p factor, and blood vessel and lymphatic invasion. Multivariable analysis indicated only 2 independent prognostic factors--cN and p factor. CONCLUSIONS: CTLC appears to belong to a subgroup other than peripheral tumors, requiring a more accurate diagnosis of cT factors, particularly in the proximal bronchus, because cT and cN factors are the only 2 used preoperatively.     

Prevention and management of perioperative arrhythmias in the thoracic surgical population

Although bradyarrhythmias or malignant ventricular tachyarrhythmias have been reported in less than 1% of patients following noncardiac surgery, rapid atrial arrhythmias more frequently affect the elderly who undergo thoracic operations. This article focuses on new issues leading to the improved understanding of the pathophysiology and mechanisms of postoperative atrial arrhythmias. It discusses new risk factors and a prediction rule for postthoracotomy atrial fibrillation (AF), reviews prophylaxis and acute therapeutic interventions for postthoracotomy AF, and highlights the most recent recommendations of the American Heart Association Task Force on the management of patients who have AF with emphasis on preventing thromboembolic events.     

Can pneumonectomy for non-small cell lung cancer be avoided? An audit of parenchymal sparing lung surgery.

BACKGROUND: Lung cancer resection rates are suboptimal in the UK. Pneumonectomy has a higher perioperative mortality risk than lobectomy. To increase resection rates and improve outcomes we have implemented a policy of parenchymal sparing surgery for tumours involving a main stem bronchus. METHODS: In a prospective 4 year study of 119 consecutive patients operated upon by a single surgeon the perioperative course, pathology and survival were compared for 81 patients undergoing pneumonectomy and 38 patients in whom pneumonectomy was avoided by bronchoplastic+/-angioplastic procedures. RESULTS: The rate of pneumonectomy decreased significantly with increasing experience with parenchymal sparing surgery (R(2)=0.98, P<0.001) with 21 of the last 30 patients (70%) avoiding pneumonectomy. There were no significant inter-group differences in patient characteristics, perioperative course or outcome. One-year survival was 64% after pneumonectomy and 73% after sleeve lobectomy. However the perioperative loss of respiratory function was significantly lower in the patients in whom pneumonectomy was avoided (P=0.0003). CONCLUSIONS: Pneumonectomy can be avoided in a large proportion of patients with non-small cell lung cancer of a main stem bronchus without adversely affecting outcome but with preservation of lung function     

Natriuretic peptides after pulmonary resection

BACKGROUND: Little is known about alterations in the levels and influence of natriuretic peptide (NP) on cardiopulmonary function after pulmonary resection for lung cancer. This study was designed to investigate the patterns and activity of NP after pulmonary resection. METHODS: We investigated changes in plasma A-type (atrial) NP and B-type (brain) NP (BNP) using radioimmunoassay, in lung cancer patients before and after lobectomy (n = 15) or pneumonectomy (n = 10). Patient characteristics, respiratory function, operative time, blood loss, intraoperative fluid administration, and intraoperative urine output in both groups were also compared. Pulmonary hemodynamic variables were monitored continuously. RESULTS: Plasma concentrations of A-type NP and BNP did not differ between the two groups preoperatively. However, the group undergoing pneumonectomy exhibited higher concentrations of A-type NP and BNP than the group undergoing lobectomy on postoperative days 3 and 7. Alterations in A-type NP and BNP after pulmonary resection therefore differed according to the volume of lung tissue resected. Both mean pulmonary artery pressure and total pulmonary vascular resistance increased significantly in the pneumonectomy group. The total pulmonary vascular resistance on postoperative day 3 correlated with the plasma BNP concentration in the pneumonectomy group. CONCLUSIONS: A-type NP and BNP effectively compensate for the right ventricular dysfunction noted after pulmonary resection, and this is more evident after pneumonectomy than after lobectomy. Changes in ventricular activity associated with changes in plasma BNP and total pulmonary vascular resistance are indicative of cardiopulmonary adjustments after pneumonectomy.     

Evaluation of lung function as a prognostic index before and after surgical resection due to NSCLC

BACKGROUND: Although there were several studies on survival, death and morbidity rates after lung resection, considering both limited and extended resections, lung exercise capacity has been quite seldom taken into account as an index for prognosis. The aim of this study compare the consequences of three kinds of lung resections (pneumonectomy, lobectomy and wedge resection), to test pre- and post-surgery exercise capacity for patients affected by NSCLC in order to obtain more detailed prognostic indices. METHODS: All the patients were studied by means of thorough lung static function and hemogas analytical tests before and after surgical resection, from 15 days to 12 twelve months' time past surgery. RESULTS: In fact, in relation to lung resection due to neoplasms, several studies pointed out that zone-limited resections show an obvious anatomical benefit in terms of parenchyma spair compared to lobectomy; however, it is underlined that the functional benefits of small resections don't really prevail over post-lobectomy anatomical advantages. Furthermore local relapses are more common after small resections rather than after lobectomy. CONCLUSIONS: Neither limited lung resection nor lobectomy alone, therefore, in accordance with nearly all the recent and still ongoing studies in this huge research field, has a significant effect on exercise capacity. Only pneumonectomy is associated with impaired exercise performance, and, nevertheless, quite below our expectations.     

Use of landiolol hydrochloride for the prevention of atrial fibrillation after lung resection

BACKGROUND: We examined the effect of landiolol hydrochloride, a selective beta1-adrenoreceptor antagonist, on the incidence of atrial fibrillation(AF). METHODS: The incidence of AF after lung resection was evaluated retrospectively in patients with intraoperative treatment with landiolol hydrochloride or those without it. Landiolol hydrochloride (5 microg x kg(-1) x min(-1)) was administered intravenously from the beginning of anesthesia induction to the end of operation. RESULTS: In non-treatment group with landiolol hydrochloride (224 patients), the incidence of AF after surgery was 14.2%, peaking on postoperative day 2, and the average peak day was day 3.5. Older age, removal of the lymph nodes, lengthy surgery, and ischemic heart failure were risk factors. In treatment group with landiolol hydrochloride (77 patients), the incidence of AF after surgery was 5.2%, which was significantly lower than that in non-treatment group. Increased numbers of risk factors led to the high incidence of AF. But the administration of landiolol hydrochloride suppressed the incidence of AF. CONCLUSIONS: Landiolol hydrochloride is effective for the preventionof AF and it is safe without causing a severe decrease in blood pressure and bradycardia in high risk patients.     

Surgical treatment for bilateral multiple lung cancers]

We reviewed 21 patients with bilateral multiple bronchogenic carcinomas. Eleven of them had synchronous carcinomas and 10 had metachronous carcinomas. We treated 6 patients with lobectomy and wedge resection under median sternotomy synchronously, and 2 patients with lobectomy on both lungs under standard thoracotomy, 2 patients with lobectomy and wedge resection, 1 patient with segmentectomy on both lung, 1 patient with lobectomy and segmentectomy, 1 patient with pneumonectomy and wedge resection, and 8 patients with lobectomy and thoracoscopic wedge resection on each lung metachronously. Two patients who had lobectomy on both lungs were dead, one of whom of pulmonary edema 2 weeks after second operation and the other of respiratory failure 3 years after second operation. We concluded that lobectomy on both lungs are not recommended because of high mortality rate (10%) and the limited resection under thoracoscopic surgery should be considered to treat the other contra lateral primary lung cancers.     

Beating-heart surgical treatment of atrial fibrillation with microwave ablation

BACKGROUND: In this feasibility study, early results are presented of our first series of patients with microwave ablation for atrial fibrillation (AF) on the beating heart. METHODS: From June 2001 until December 2001, a total of 24 patients underwent beating-heart epicardial ablation for AF. With a microwave antenna, the left and right pulmonary veins were isolated and connected to each other followed by amputation of the left atrial appendage. Subsequently, patients underwent either off-pump coronary artery bypass graft or valve surgery on pump. The mean age of the patients was 67.4 +/- 6 years. Three patients experienced paroxysmal atrial fibrillation and all others chronic AF. Mean left atrial diameter was 5.4 +/- 0.6 cm, and mean ablation time was 13 min. RESULTS: All procedures but one were completed successfully on the beating heart. All patients were in sinus rhythm after the procedure. A total of 15 patients experienced periods with postoperative AF during hospital stay; 9 of these patients were discharged with AF. All patients received either sotalol or amiodarone. At latest follow-up (3 to 9 months), 20 of 23 patients were in sinus rhythm. CONCLUSIONS: With microwave ablation, electrical isolation of the pulmonary veins can be achieved epicardially without cardiopulmonary bypass support.     

肺肿瘤切除和心脏同期手术14例

目的 对肺部肿瘤同时伴有严重心脏疾病的病人采用同期肺切除和心脏手术方法治疗.方法 2003年至2008年,共完成肺肿瘤切除和心脏同期手术14例,其中男11例,女3例,平均年龄64岁.同期手术中肺叶切除9例,肺楔形切除5例;其中鳞癌4例、腺癌6例、未分化癌1例、错构瘤2例、硬化性血管瘤1例.同期心脏手术为冠状动脉旁路移植术12例,二尖瓣置换及二尖瓣修复加射频消融各1例.结果 全组无手术死亡和术后开胸止血.1例术后发生房颤很快转复,1例发生肺炎、ARDS,经气管切开等治疗后痊愈出院.结论 冠状动脉不停跳旁路移植手术手术风险明显减少,为保证肺癌治疗效果在同期手术中采取第二切口行肺切除和系统纵隔淋巴结清扫,此法手术并发症少且病人可接受.     

Effects of diltiazem prophylaxis on the incidence and clinical outcome of atrial arrhythmias after thoracic surgery

OBJECTIVES: We sought to determine whether early prophylaxis with an L -type calcium channel blocker reduces the incidence and morbidity associated with atrial fibrillation/flutter and supraventricular tachyarrhythmia after major thoracic operations. METHODS: In this randomized, double-blind, placebo-controlled study, 330 patients were given either intravenous diltiazem (n = 167) or placebo (n = 163) immediately after lobectomy (> or =60 years) or pneumonectomy (> or =18 years) and orally thereafter for 14 days. The primary end point with respect to efficacy was a sustained (> or =15 minutes) or clinically significant atrial arrhythmia during treatment. RESULTS: Postoperative atrial arrhythmias (atrial fibrillation/flutter = 60; supraventricular tachyarrhythmias = 5) occurred in 25 (15%) of the 167 patients in the diltiazem group and 40 (25%) of the 163 patients in the placebo group (P = .03). When compared with placebo, diltiazem nearly halved the incidence of clinically significant arrhythmias (17/167 [10%] vs. 31/163 [19%], P = .02). The 2 groups did not differ in the incidence of other major postoperative complications or overall duration or costs of hospitalization. No serious adverse effects caused by diltiazem were seen. CONCLUSIONS: After major thoracic operations, prophylactic diltiazem reduced the incidence of clinically significant atrial arrhythmias in patients considered at high risk for this complication.