Risk factors for intermediate-term survival after coronary artery bypass grafting

Comparison of Multidimensional Frailty Instruments for Estimation of Long-term Patient-Centered Outcomes After Cardiac Surgery

Importance

Little is known about the performance of available frailty instruments in estimating patient-relevant outcomes after cardiac surgery.

Objective

To examine how well the Johns Hopkins Adjusted Clinical Groups (ACG) frailty indicator, the Hospital Frailty Risk Score (HFRS), and the Preoperative Frailty Index (PFI) estimate long-term patient-centered outcomes after cardiac surgery.

Design, Setting, and Participants

This retrospective cohort study was conducted in Ontario, Canada, among residents 18 years and older who underwent coronary artery bypass grafting or aortic, mitral or tricuspid valve, or thoracic aorta surgery between October 2008 and March 2017. Long-term care residents, those with discordant surgical encounters, and those receiving dialysis or dependent on a ventilator within 90 days were excluded. Statistical analysis was conducted from July 2021 to January 2022.

Main Outcomes and Measures

The primary outcome was patient-defined adverse cardiovascular and noncardiovascular events (PACE), defined as the composite of severe stroke, heart failure, long-term care admission, new-onset dialysis, and ventilator dependence. Secondary outcomes included mortality and individual PACE events. The association between frailty and PACE was examined using cause-specific hazard models with death as a competing risk, and the association between frailty and death was examined using Cox models. Areas under the receiver operating characteristic curve (AUROC) were determined over 10 years of follow-up for each frailty instrument.

Results

Of 88 456 patients (22 924 [25.9%] female; mean [SD] age, 66.3 [11.1] years), 14 935 (16.9%) were frail according to ACG criteria, 63 095 (71.3%) according to HFRS, and 76 754 (86.8%) according to PFI. Patients with frailty were more likely to be older, female, and rural residents; to have lower income and multimorbidity; and to undergo urgent surgery. Patients meeting ACG criteria (hazard ratio [HR], 1.66; 95% CI, 1.60-1.71) and those with higher HFRS scores (HR per 1.0-point increment, 1.10; 95% CI, 1.09-1.10) and PFI scores (HR per 0.1-point increment, 1.75; 95% CI, 1.73-1.78) had higher rates of PACE. Similar magnitudes of association were observed for each frailty instrument with death and individual PACE components. The HFRS had the highest AUROC for estimating PACE during the first 2 years and death during the first 4 years, after which the PFI had the highest AUROC.

Conclusions and Relevance

These findings could help to tailor the use of frailty instruments by outcome and follow-up duration, thus optimizing preoperative risk stratification, patient-centered decision-making, candidate selection for prehabilitation, and personalized monitoring and health resource planning in patients undergoing cardiac surgery.

Short-term and long-term impact of diagnosed and undiagnosed chronic obstructive pulmonary disease on coronary artery bypass grafting surgery

OBJECTIVES

This study sought to compare clinical outcomes between three categories of patients: non-chronic obstructive pulmonary disease (COPD), diagnosed COPD and undiagnosed COPD in coronary artery bypass grafting surgery.

METHODS

A single-centred retrospective study from January 2010 to December 2019. Primary outcomes were postoperative complications, length of ITU admission and in-hospital staying. Secondary outcomes were reintervention rate, in-hospital and long-term mortality.

RESULTS

A total of 4020 patients were analysed and divided into three cohorts: non-COPD (group A) (74.55%, n=2997), diagnosed COPD (group B) (14.78%, n=594) and undiagnosed COPD (group C) (10.67%, n=429). The rate of respiratory complications was noted in this order: group B>group C>group A (p 0.00000002). Periooperative acute kidney injury and wound complications were higher in group B (p 0.0004 and p 0.03, respectively). Prolonged in-hospital staying (days) resulted in group B (p 0.0009). Finally, long-term mortality was statistically higher in group B and C compared with group A (p 0.0004). No difference in long-term mortality was noted in relation to the expected FEV1% in group B (p 0.29) and group C (p 0.82).

CONCLUSIONS

In CABG surgery, COPD is a well-known independent risk factor for morbidity. Patients with preoperative spirometry results indicative of COPD result in the same outcomes of known patients with COPD. As a result of that, greater value should be given to the preoperative spirometry in the EuroSCORE. Finally, the expected FEV1% appears not be a predictor for long-term survival.

Frailty, disability and comorbidity: different domains lead to different effects after surgical aortic valve replacement in elderly patients

OBJECTIVES

Frailty syndrome predicts adverse outcomes after surgical aortic valve replacement. However, disability or comorbidity is frequently associated with preoperative frailty evaluation. The effects of these domains on early and late outcomes were analysed.

METHODS

A prospective study including patients aged ≥75 years with symptomatic severe aortic stenosis who received aortic valve replacement with or without coronary artery bypass grafting was conducted. We used the Cardiovascular Health Study Frailty Phenotype to assess frailty, the Lawton-Brody index to define disability and the Charlson comorbidity index (CCI) to evaluate comorbidity.

RESULTS

Frailty was identified in 57 (31%), dependence in 18 (9.9%) and advanced comorbidity (CCI ≥ 4) in 67 (36.6%) of the 183 enrolled patients. Operative mortality (1.6%), transfusion rate and duration of stay increased in patients with CCI ≥4 (P < 0.005). There was a non-significant trend for these adverse outcomes among the frail patients. Follow-up was achieved in all patients (median/interquartile range 869/699-1099 days). Kaplan-Meier univariable analysis showed a reduced survival rate for frail and dependent patients and for those with multiple comorbidities (P < 0.05). According to multivariable analysis, frailty and comorbidity were independent risk factors for 1-year mortality, while disability and comorbidity, but not frailty, were risk factors for 3-year mortality (P < 0.05).

CONCLUSIONS

Surgical aortic valve replacement in patients aged ≥75 years is a safe procedure with low mortality rates. Operative outcomes are mainly affected by comorbidities. The main influence of survival occurs throughout the first year, and an improved functional status prevents any progression towards disabilities, which could potentially benefit long-term outcomes.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02745314.

Predictors of long-term prognosis in acute kidney injury survivors who require continuous renal replacement therapy after cardiovascular surgery

The long-term prognosis of patients with postoperative acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) after cardiovascular surgery is unclear. We aimed to investigate long-term renal outcomes and survival in these patients to determine the risk factors for negative outcomes. Long-term prognosis was examined in 144 hospital survivors. All patients were independent and on renal replacement therapy at hospital discharge. The median age at operation was 72.0 years, and the median pre-operative estimated glomerular filtration rate (eGFR) was 39.5 mL/min/1.73 m2. The median follow-up duration was 1075 days. The endpoints were death, chronic maintenance dialysis dependence, and a composite of death and chronic dialysis. Predictors for death and dialysis were evaluated using Fine and Gray's competing risk analysis. The cumulative incidence of death was 34.9%, and the chronic dialysis rate was 13.3% during the observation period. In the multivariate proportional hazards analysis, eGFR <30 mL/min/1.73 m2 at discharge was associated with the composite endpoint of death and dialysis [hazard ratio (HR), 2.1; 95% confidence interval (CI), 1.1-3.8; P = 0.02]. Hypertension (HR 8.7, 95% CI, 2.2-35.4; P = 0.002) and eGFR <30 mL/min/1.73 m2 at discharge (HR 26.4, 95% CI, 2.6-267.1; P = 0.006) were associated with dialysis. Advanced age (≥75 years) was predictive of death. Patients with severe CRRT-requiring AKI after cardiovascular surgery have increased risks of chronic dialysis and death. Patients with eGFR <30 mL/min/1.73 m2 at discharge should be monitored especially carefully by nephrologists due to the risk of chronic dialysis and death.

Association of Frailty and Long-Term Survival in Patients Undergoing Coronary Artery Bypass Grafting

BACKGROUND

Frailty is increasing in prevalence and poses a formidable challenge for clinicians. The cardiac surgery literature consists primarily of small single-center studies with limited follow-up, and the epidemiological features of frailty remain to be elucidated in long-term follow-up.

METHODS AND RESULTS

We conducted a population-based, retrospective, cohort study in Ontario, Canada, between 2008 and 2015. Frailty was defined using the Johns Hopkins Adjusted Clinical Groups frailty indicator (a multidimensional instrument validated for research using administrative data). The primary outcome was mortality. Mortality rates were calculated using the Kaplan-Meier method. The hazard of death was assessed using a multivariable Cox proportional hazard model. Of 40 083 patients, 8803 (22%) were frail. At 4±2 years of follow-up, age- and sex-standardized mortality rate per 1000 person-years was higher in frail (33; 95% confidence interval, 29-36) compared with nonfrail (22; 95% confidence interval, 19-24) patients. Frailty was associated with an increased risk of long-term mortality (adjusted hazard ratio, 1.20; 95% confidence interval, 1.12-1.28) and greater differences in the survival of patients between 40 and 74 years of age than in those who were ≥85 years old.

CONCLUSIONS

Frailty was present in a large proportion of patients undergoing coronary artery bypass grafting and was independently associated with long-term mortality. The adjusted risk of frailty-related death was inversely proportional to age. Our findings highlight the need for more comprehensive preoperative risk stratification models to assist with optimal selection of operative candidates. In addition, we identified the <75 years age group as a potential target for comprehensive preoperative optimization programs, such as cardiac prehabilitation, nutritional augmentation, and psychosocial support.

Oxygen dependence of endothelium-dependent vasodilation: importance in chronic obstructive pulmonary disease

INTRODUCTION

Epidemiological studies have shown increased morbidity and mortality in patients with coronary artery disease (CAD) and chronic obstructive pulmonary disease (COPD). We aimed to characterize the oxygen dependence of endothelial function in patients with CAD and coexisting COPD.

MATERIAL AND METHODS

In CAD patients with and without COPD (n = 33), we non-invasively measured flow-mediated dilation (FMD) and intima-media thickness (IMT) of the brachial artery (BA), forearm blood flow (FBF), and perfusion of the cutaneous microcirculation with laser Doppler perfusion imaging (LDPI). In an experimental setup, vascular function was assessed in healthy volunteers (n = 5) breathing 12% oxygen or 100% oxygen in comparison to room air.

RESULTS

COPD was associated with impaired FMD (3.4 ±0.5 vs. 4.2 ±0.6%; p < 0.001) and increased IMT (0.49 ±0.04 vs. 0.44 ±0.04 mm; p <0.01), indicating functional and structural alterations of the BA in COPD. Forearm blood flow and LDPI were comparable between the groups. Flow-mediated dilation correlated with capillary oxygen pressure (pO2, r = 0.608). Subgroup analysis in COPD patients with pO2 > 65 mm Hg and pO2 ≤ 65 mm Hg revealed even lower FMD in patients with lower pO2 (3.0 ±0.5 vs. 3.7 ±0.4%; p < 0.01). Multivariate analysis showed that pO2 was a predictor of FMD independent of the forced expiratory volume and pack years. Exposure to hypoxic air led to an acute decrease in FMD, whereby exposure to 100% oxygen did not change vascular function.

CONCLUSIONS

Our data suggest that in CAD patients with COPD, decreased systemic oxygen levels lead to endothelial dysfunction, underlining the relevance of cardiopulmonary interaction and the potential importance of pulmonary treatment in secondary prevention of vascular disease.

Minimally invasive valve surgery in high-risk patients

The use of minimally, or less invasive, approaches to cardiac valve surgery has increased over the past decade. Because of its less traumatic nature, early studies in lower risk patients demonstrated the approach to be associated with an enhanced recovery, increased patient satisfaction, and good operative outcomes. With time, despite a steep learning curve, surgeons expanded this approach to perform more complex procedures, and include patients with more co-morbidity. The aim of this publication is to review the current literature involving the use of minimally invasive valve surgery (MIVS) in higher-risk patients.

Outcomes and long-term survival of coronary artery surgery: The controversial role of opium as risk marker

AIM

To study survival in isolated coronary artery bypass graft (CABG) patients and to evaluate the impact of preoperative chronic opium consumption on long-term outcome.

METHODS

Cohort of 566 isolated CABG patients as Tehran Heart Center cardiac output measurement was conducted. Daily evaluation until discharge as well as 4- and 12-mo and 6.5-year follow-up information for survival status were fulfilled for all patients. Long-term 6.5-year overall and opium-stratified survival, adjusted survival curves based on opium consumption as well as possible predictors of all-cause mortality using multiple cox regression were determined by statistical analysis.

RESULTS

Six point five-year overall survival was 91.8%; 86.6% in opium consumers and 92.7% in non-opium consumers (P = 0.035). Patients with positive history of opium consumption significantly tended to have lower ejection fraction (EF), higher creatinine level and higher prevalence of myocardial infarction. Multiple predictors of all-cause mortality included age, body mass index, EF, diabetes mellitus and cerebrovascular accident. The hazard ratio (HR) of 2.09 for the risk of mortality in opium addicted patients with a borderline P value (P = 0.052) was calculated in this model. Further adjustment with stratification based on smoking and opium addiction reduced the HR to 1.20 (P = 0.355).

CONCLUSION

Simultaneous impact of smoking as a confounding variable in most of the patients prevents from definitive judgment on the role of opium as an independent contributing factor in worse long-term survival of CABG patients in addition to advanced age, low EF, diabetes mellitus and cerebrovascular accident. Meanwhile, our findings do not confirm any cardio protective role for opium to improve outcome in coronary patients with the history of smoking. Further studies are needed to clarify pure effect of opium and warrant the aforementioned findings.

Preoperative Frailty Assessment and Outcomes at 6 Months or Later in Older Adults Undergoing Cardiac Surgical Procedures: A Systematic Review

BACKGROUND

Frailty assessment may inform surgical risk and prognosis not captured by conventional surgical risk scores.

PURPOSE

To evaluate the evidence for various frailty instruments used to predict mortality, functional status, or major adverse cardiovascular and cerebrovascular events (MACCEs) in older adults undergoing cardiac surgical procedures.

DATA SOURCES

MEDLINE and EMBASE (without language restrictions), from their inception to 2 May 2016.

STUDY SELECTION

Cohort studies evaluating the association between frailty and mortality or functional status at 6 months or later in patients aged 60 years or older undergoing major or minimally invasive cardiac surgical procedures.

DATA EXTRACTION

2 reviewers independently extracted study data and assessed study quality.

DATA SYNTHESIS

Mobility, disability, and nutrition were frequently assessed domains of frailty in both types of procedures. In patients undergoing major procedures (n = 18 388; 8 studies), 9 frailty instruments were evaluated. There was moderate-quality evidence to assess mobility or disability and very-low- to low-quality evidence for using a multicomponent instrument to predict mortality or MACCEs. No studies examined functional status. In patients undergoing minimally invasive procedures (n = 5177; 17 studies), 13 frailty instruments were evaluated. There was moderate- to high-quality evidence for assessing mobility to predict mortality or functional status. Several multicomponent instruments predicted mortality, functional status, or MACCEs, but the quality of evidence was low to moderate. Multicomponent instruments that measure different frailty domains seemed to outperform single-component ones.

LIMITATION

Heterogeneity of frailty assessment, limited generalizability of multicomponent frailty instruments, few validated frailty instruments, and potential publication bias.

CONCLUSION

Frailty status, assessed by mobility, disability, and nutritional status, may predict mortality at 6 months or later after major cardiac surgical procedures and functional decline after minimally invasive cardiac surgery.

PRIMARY FUNDING SOURCE

National Institute on Aging and National Heart, Lung, and Blood Institute.

Reduced Long-Term Relative Survival in Females and Younger Adults Undergoing Cardiac Surgery: A Prospective Cohort Study

OBJECTIVES

To assess long-term survival and mortality in adult cardiac surgery patients.

METHODS

8,564 consecutive patients undergoing cardiac surgery in Trondheim, Norway from 2000 until censoring 31.12.2014 were prospectively followed. Observed long-term mortality following surgery was compared to the expected mortality in the Norwegian population, matched on gender, age and calendar year. This enabled assessment of relative survival (observed/expected survival rates) and relative mortality (observed/expected deaths). Long-term mortality was compared across gender, age and surgical procedure. Predictors of reduced survival were assessed with multivariate analyses of observed and relative mortality.

RESULTS

During follow-up (median 6.4 years), 2,044 patients (23.9%) died. The observed 30-day, 1-, 3- and 5-year mortality rates were 2.2%, 4.4%, 8.2% and 13.8%, respectively, and remained constant throughout the study period. Comparing observed mortality to that expected in a matched sample from the general population, patients undergoing cardiac surgery showed excellent survival throughout the first seven years of follow-up (relative survival ≥ 1). Subsequently, survival decreased, which was more pronounced in females and patients undergoing other procedures than isolated coronary artery bypass grafting (CABG). Relative mortality was higher in younger age groups, females and patients undergoing aortic valve replacement (AVR). The female survival advantage in the general population was obliterated (relative mortality ratio (RMR) 1.35 (1.19-1.54), p<0.001). Increasing observed long-term mortality seen with ageing was due to population risk, and younger age was independently associated with increased relative mortality (RMR per 5 years 0.81 (0.79-0.84), p<0.001)).

CONCLUSIONS

Cardiac surgery patients showed comparable survival to that expected in the general Norwegian population, underlining the benefits of cardiac surgery in appropriately selected patients. The beneficial effect lasted shorter in younger patients, females and patients undergoing AVR or other procedures than isolated CABG. Thus, the study identified three groups that need increased attention for further improvement of outcomes.

Predictors for long-term outcome and quality of life of patients after cardiac surgery with prolonged intensive care unit stay

OBJECTIVES

This study investigated factors determining the long-term outcome and quality of life of patients with a prolonged intensive care unit (ICU) stay after cardiac surgery.

DESIGN

A retrospective analysis was performed in 230 patients that had undergone cardiac surgery and suffered from a post-operative ICU stay of 7 or more days at our institution. Among 11 pre-, 13 intra-, and 14 post-operative variables, factors influencing 5-year outcome were identified by logistic regression analysis. Quality of life was determined using the Short Form-36 questionnaire.

RESULTS

In-hospital mortality was 12%. One hundred and eleven of 187 patients (59%) were alive after 5 years. Non-survivors were older (70 vs. 65 years, p = 0.005) and had a higher additive EuroSCORE (7 vs. 5, p = 0.034). Logistic regression identified pre-operative atrial fibrillation (AF), (28 vs. 10%, p = 0.003) as the strongest predictor for a 5-year outcome, followed by myocardial infarction (62 vs. 41%, p = 0.005), and prolonged mechanical ventilation (8 vs. 5 days, p = 0.036). Survivors did not show an impaired physical component summary SF-36 score (39 vs. 46, p = 0.737) or mental component summary score (55 vs. 55, p = 0.947) compared to an age-matched German Normative Sample.

CONCLUSIONS

Pre-operative AF proved to be the most important factor determining the 5-year outcome of patients with a prolonged ICU stay after cardiac surgery. Neither physical nor mental health appeared to be impaired in these patients.

Outcomes of minimally invasive valve surgery in patients with chronic obstructive pulmonary disease

OBJECTIVES

We hypothesize that minimally invasive valve surgery in patients with chronic obstructive pulmonary disease (COPD) is superior to the conventional median sternotomy approach.

METHODS

We retrospectively reviewed 2846 consecutive surgery performed at our institution between January 2005 and September 2010, and identified 165 patients with COPD who underwent isolated valve surgery. In-hospital mortality, composite complication rates, intensive care unit and total hospital length of stay of those who had undergone a minimally invasive approach were compared with a cohort that underwent a standard median sternotomy approach.

RESULTS

Of the 165 patients, 100 underwent a minimally invasive approach and 65 had a median sternotomy. Baseline characteristics did not differ between the two groups. The mean age was 71 ± 11 years for the minimally invasive group and 68 ± 12 years for the median sternotomy group, (P = 0.31). In-hospital mortality was 1 (1%) in the minimally invasive group and 3 (5%) in the median sternotomy group, P = 0.14. Composite postoperative complications were significantly reduced in the minimally invasive group (30 versus 54%, P = 0.002). The median intensive care unit length of stay was 47 h (IQR 40-70) versus 73 h (IQR 51-112), P < 0.001, and the median postoperative length of stay was 6 days (IQR 5-9) versus 9 days (IQR 7-13), P < 0.001, for the minimally invasive and the median sternotomy groups, respectively.

CONCLUSIONS

Minimally invasive valve surgery in patients with COPD is associated with excellent short-term results, and thus should be considered an option in these patients.

Risk score for predicting long-term mortality after coronary artery bypass graft surgery

BACKGROUND

No simplified bedside risk scores have been created to predict long-term mortality after coronary artery bypass graft surgery.

METHODS AND RESULTS

The New York State Cardiac Surgery Reporting System was used to identify 8597 patients who underwent isolated coronary artery bypass graft surgery in July through December 2000. The National Death Index was used to ascertain patients' vital statuses through December 31, 2007. A Cox proportional hazards model was fit to predict death after CABG surgery using preprocedural risk factors. Then, points were assigned to significant predictors of death on the basis of the values of their regression coefficients. For each possible point total, the predicted risks of death at years 1, 3, 5, and 7 were calculated. It was found that the 7-year mortality rate was 24.2 in the study population. Significant predictors of death included age, body mass index, ejection fraction, unstable hemodynamic state or shock, left main coronary artery disease, cerebrovascular disease, peripheral arterial disease, congestive heart failure, malignant ventricular arrhythmia, chronic obstructive pulmonary disease, diabetes mellitus, renal failure, and history of open heart surgery. The points assigned to these risk factors ranged from 1 to 7; possible point totals for each patient ranged from 0 to 28. The observed and predicted risks of death at years 1, 3, 5, and 7 across patient groups stratified by point totals were highly correlated.

CONCLUSION

The simplified risk score accurately predicted the risk of mortality after coronary artery bypass graft surgery and can be used for informed consent and as an aid in determining treatment choice.

Predictors and Outcomes of Prolonged Ventilation after Coronary Artery Bypass Graft Surgery

This study investigated and compared the risk factors and outcomes of patients undergoing coronary artery bypass graft surgery with and without the occurrence of prolonged mechanical ventilation. Data in a cardiac surgery database were examined retrospectively. Data selected included any isolated coronary artery bypass graft surgery performed by the surgical group from August 2005 to June 2009. The resulting cohort included a total of 2933 patients which was comprised of 116 patients with a ventilation time of greater than 72 hours (prolonged ventilation) and 2817 patients with a ventilation time of 72 hours or less (no prolonged ventilation). Patients with a prolonged ventilation time were matched (1:3 ratio) to patients not requiring a prolonged ventilation time by year of surgery resulting in our study cohort of 464 patients. To generate the unadjusted risks of each factor, χ2 and t test analysis were performed. Logistic regression analysis was then used to investigate the adjusted risk between cases and controls and each of the significant variables. χ2 and t tests were conducted comparing cases and controls with the outcome variables. Patients undergoing coronary artery bypass graft that experienced a prolonged ventilation time (cases) were more likely female, had a New York Hospital Association functional class of III or IV, and had a longer perfusion time. There was no significant difference between cases and controls with diabetes, chronic obstructive pulmonary disease, left ventricular ejection fraction, or body mass index while controlling for all significant risk factors. Careful patient selection and preparation during preoperative evaluation may help identify patients at risk for prolonged mechanical ventilation and thus help prevent the added morbidity and mortality associated with it.

Changes in cysteinyl leukotrienes during and after cardiac surgery with cardiopulmonary bypass in patients with and without chronic obstructive pulmonary disease

OBJECTIVE

Pulmonary function frequently deteriorates after cardiopulmonary bypass (CPB). Chronic obstructive pulmonary disease (COPD) increases risk of respiratory complications after CPB. Cysteinyl leukotrienes are important mediators of respiratory dysfunction. Their role during cardiac surgery and its lung complications is incompletely understood. We studied whether production of cysteinyl leukotrienes changes during and after cardiac surgery with CPB and differs between patients with and without COPD.

METHODS

Patients with (n = 9) and without (n = 10) moderate-to-severe COPD undergoing cardiac surgery with CPB were prospectively included. Plasma and urinary cysteinyl leukotriene and leukotriene B(4) concentrations were measured by enzyme-linked immunosorbent assay after anesthesia induction, at end of CPB, after CPB, and 2 hours after intensive care unit admission. Gas exchange and respiratory mechanics were also assessed.

RESULTS

Patients with COPD had larger airway resistances after CPB and chest closure (P < .001), lower ratio of arterial Po(2) to inspired oxygen fraction at intensive care unit admission (215 ± 37 vs 328 ± 30 mm Hg, P < .05), and longer postoperative mechanical ventilation (13.7 ± 5.8 vs 6.8 ± 3.4 hours, P < .01). Urinary cysteinyl leukotriene concentrations increased with time in both groups (P < .01), but more in patients with than without COPD (P < .05). Plasma cysteinyl leukotriene concentrations increased significantly between baseline and intensive care unit admission in patients with but not without COPD (P < .01). Concentrations of leukotriene B(4) in plasma and urine did not increase significantly with time and were not different between groups.

CONCLUSIONS

Release of cysteinyl leukotrienes increases during cardiac surgery with CPB and is larger in patients with than without COPD. This may be related to higher lung and airway production of cysteinyl leukotrienes and neutrophil activation in patients with COPD.

Preoperative pulmonary function and mortality after cardiac surgery

BACKGROUND

The aim of the study was to examine the relationship between preoperative pulmonary function and outcomes after cardiac surgery.

METHODS

We performed preoperative pulmonary function tests (PFTs) in 1,169 patients undergoing cardiac surgery at the Minneapolis Veterans Affairs Medical Center. Airway obstruction was defined as forced expiratory volume in 1 minute (FEV(1)) to forced vital capacity ratio <0.7.

RESULTS

Of the 1,169 patients, 483 (41%) had a prior history of chronic obstructive pulmonary disease (COPD). However, 178 patients with a history of COPD had no airway obstruction on PFT. Conversely, 186 patients without a COPD history had airway obstruction on PFT. Thus, PFT results helped reclassify the COPD status of 364 patients (31%). Operative mortality was 2% in patients with no or mild airway obstruction versus 6.7% in those with moderate or severe obstruction (ie, FEV(1) to forced vital capacity ratio <0.7 and FEV(1) <80% predicted). Postoperative mortality was higher (odds ratio 3.2, 95% CI 1.6-6.2, P = .001) in patients with moderate or severe airway obstruction and in patients with diffusing capacity of the lung for carbon monoxide <50% of predicted (odds ratio 4.9, 95% CI 2.3-10.8, P = .0001). Notably, mortality risk was 10x higher (95% CI 3.4-27.2, P = .0001) in patients with moderate or severe airway obstruction and diffusing capacity of the lung for carbon monoxide <50% of predicted.

CONCLUSIONS

These data show that PFT before cardiac surgery reclassifies the COPD status of a substantial number of patients and provides important prognostic information that the current risk estimate models do not capture.

The use of spirometry testing prior to cardiac surgery may impact the Society of Thoracic Surgeons risk prediction score: a prospective study in a cohort of patients at high risk for chronic lung disease

OBJECTIVES

Chronic lung disease is a significant comorbidity in patients undergoing cardiac surgery. Chronic lung disease is currently being classified and reported to the Society of Thoracic Surgeons database by using either clinical interview or spirometric testing. We sought to compare the chronic lung disease classification captured by the 2 methods.

METHODS

We performed a prospectively designed study in which patients presenting for cardiac surgery, excluding emergent patients, were screened for a history of asthma, a history of 10 or more pack-years of smoking, a persistent cough, and the use of oxygen. Each selected patient underwent spirometry. The presence and severity of chronic lung disease was coded per Society of Thoracic Surgeons guidelines by using the 2 methods of clinical report and spirometric results. The chronic lung disease classifications were compared, and differences were determined by using concordance and discordance rates. The results were then used to construct Society of Thoracic Surgeons-predicted risk models.

RESULTS

The discordant rate was 39.1%, with underestimation of the severity of chronic lung disease in 94% of misclassified patients. This affected the Society of Thoracic Surgeons-predicted risk models for prolonged ventilation, morbidity/mortality, and mortality by increasing the predicted risk when spirometry was used for morbidity/mortality by an average of 1.5 +/- 1.2 percentage points (P < .001) and prolonged ventilation time by an average of 1.3 +/- 1.4 percentage points (P < .001).

CONCLUSION

The use of patient history for symptoms, medication, and/or oxygen use as the only method to determine chronic lung disease for this subgroup of patients led to underreporting of chronic lung disease and underestimation of the risk for adverse outcomes. Therefore data submission to the Society of Thoracic Surgeons database should be designed to capture and correct for potential bias in the definition of chronic lung disease because the rate of spirometry in different centers in defining chronic lung disease is not regulated.

BP variability and cardiovascular autonomic function in relation to forced expiratory volume: a population-based study

BACKGROUND

Cardiovascular autonomic dysfunction is associated with increased incidence of cardiovascular diseases. This population-based study explored whether low FEV(1) or low vital capacity (VC) is associated with autonomic dysfunction, as measured by spontaneous heart rate variability (HRV) and systolic BP variability (SBPV).

METHODS

SBPV and HRV were recorded during 5 min of controlled breathing in men and women who were 70 years of age. FEV(1) and VC were recorded in 901 subjects. Of them, information on HRV and SBPV was available in 820 and 736 subjects, respectively. Measures of autonomic function, that is, SBPV in the low-frequency (LF) and high-frequency (HF) domains, HRV, and baroreceptor sensitivity (BRS), were studied in sex-specific quartiles of FEV(1) and VC.

RESULTS

Low FEV(1) was associated with high SBPV in the HF domain. The mean SBPV-HFs were 5.2, 4.5, 4.1, and 3.8 mm Hg, respectively, in subjects with FEV(1) in the first (low), second, third, and fourth quartile (p < 0.001 [for trend]). This relationship persisted after adjustments for potential confounding factors. Low VC was significantly associated with high SBPV-HF in the crude analysis but not after adjustment for confounding factors. Neither FEV(1) nor VC showed any significant relationship with BRS, HRV, or SBPV in the LF domain.

CONCLUSION

In this population-based study, low FEV(1) was associated with high SBPV in the HF domain. It is suggested that high beat-to-beat variability in BP could contribute to the increased cardiovascular risk in subjects with moderately reduced FEV(1).

Chronic obstructive pulmonary disease is an independent predictor of death but not atherosclerotic events in patients with myocardial infarction: analysis of the Valsartan in Acute Myocardial Infarction Trial (VALIANT)

AIMS

Chronic obstructive pulmonary disease is an independent predictor of mortality in patients with myocardial infarction (MI). However, the impact on mode of death and risk of atherosclerotic events is unknown.

METHODS AND RESULTS

We assessed the risk of death and major cardiovascular (CV) events associated with chronic obstructive pulmonary disease in 14 703 patients with acute MI enrolled in the Valsartan in Acute Myocardial Infarction (VALIANT) trial. Cox proportional hazards models were used to evaluate the relationship between chronic obstructive pulmonary disease and CV outcomes. A total of 1258 (8.6%) patients had chronic obstructive pulmonary disease. Over a median follow-up period of 24.7 months, all-cause mortality was 30% in patients with chronic obstructive pulmonary disease, compared with 19% in those without. The adjusted hazard ratio (HR) for mortality was 1.14 (95% confidence interval 1.02-1.28). This reflected increased incidence of both non-CV death [HR 1.86 (1.43-2.42)] and sudden death [HR 1.26 (1.03-1.53)]. The unadjusted risk of all pre-specified CV outcomes was increased. However, after multivariate adjustment, chronic obstructive pulmonary disease was not an independent predictor of atherosclerotic events [MI or stroke: HR 0.98 (0.77-1.23)]. Mortality was significantly lower in patients receiving beta-blockers, irrespective of airway disease.

CONCLUSION

In high-risk patients with acute MI, chronic obstructive pulmonary disease is associated with increased mortality and non-fatal clinical events (both CV and non-CV). However, patients with chronic obstructive pulmonary disease did not experience a higher rate of atherosclerotic events.

Prediction of survival after coronary revascularization: modeling short-term, mid-term, and long-term survival

BACKGROUND

Many clinical prediction rules for short-term mortality after coronary revascularization have been developed, validated, and introduced into routine clinical practice. Few rules exist for predicting long-term survival in the modern era of coronary revascularization. We report on the development and validation of models for predicting long-term survival after coronary artery bypass graft surgery and percutaneous coronary intervention on the basis of recent experience.

METHODS

We linked 1987 through 2001 coronary artery bypass graft surgery and 1992 through 2001 percutaneous coronary intervention data from our northern New England registries on 35,000 patients with complete data on risk factors to the National Death Index, ascertaining 7,000 deaths. We partitioned time after revascularization into three periods on the basis of exploratory analysis using generalizations of Cox's semiparametric model to nonproportional hazards and nonlinear log-hazards. These periods were 0 to 3 months, 4 to 18 months, and 19 months and later. For each period, Cox's regression model was used to regress survival on risk factors yielding three models, which were then combined to make long-term predictions.

RESULTS

These models were incorporated into easy-to-use software that yields predicted survival for up to 8 years after revascularization. The Harrell concordance statistic ranged from 72% to 83% for these models.

CONCLUSIONS

We developed and internally validated models that accurately predict long-term survival after coronary artery bypass graft surgery and percutaneous coronary intervention as currently performed. These models using routine clinical data, can be solved with available software, and could be used to enhance informed, patient-centered clinical decision making on the choice of revascularization procedure.

Modifiable risk factors remain significant causes of medium term mortality after first time Coronary artery bypass grafting

Background

Whilst there is much current data on early outcomes after Coronary artery bypass grafting(CABG), there is relatively little data on medium term outcomes in the current era. The purpose of this study is to present a single surgeon series comprising of all first time CABG patients operated on with the technique of cross clamp fibrillation from Feb-1996 to through to Jan-2003, and to seek risk factors for medium term mortality in these patients.

Methods

Data was collected from Hospital Episode Statistics and departmental patient administration and tracking systems and cross checked using database techniques. Patient outcomes were searched using the National Health Service strategic tracing service.

Results

Mean follow up was 5.3 years(0–9.4 years) and was complete for all patients. 30-day survival was 98.4%, 1-year survival 95% and 8-year survival 79%. Cox-regression analysis revealed that several modifiable pre-operative risk factors remain significant predictors of medium term mortality, including Diabetes(Hazard Ratio(HR) 1.73, 95%CI 1.21–2.45), Chromic obstructive pulmonary disease(HR 2.02, 95%CI 1.09–3.72), Peripheral vascular disease(HR 1.68, 95%CI 1.13–2.5), Body mass index>30(HR 1.54, 95%CI 1.08–2.20) and current smoker at operation(HR 1.67, 95%CI 1.03–2.72). However hypertension(HR 1.31, 95%CI 0.95–1.82) and Hypercholestrolaemia(HR 0.81, 95%CI 0.58–1.13) were not predictive which may reflect adequate post-operative control.

Conclusion

Coronary artery bypass surgery using cross clamp fibrillation is associated with a very low operative mortality. Medium term survival is also good but risk factors such as smoking at operation, Chronic obstructive pulmonary disease, obesity and diabetes negatively impact this survival and should be aggressively treated in the years post-surgery.

Reduced lung function predicts increased fatality in future cardiac events. A population-based study

OBJECTIVE

Moderately reduced lung function in apparently healthy subjects has been associated with incidence of coronary events. However, whether lung function is related to the fatality of the future events is unknown. This study explored whether reduced forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)) in initially healthy men is related to the fatality of the future coronary events.

DESIGN

Prospective cohort study.

SETTING

Population-based study from Malmö, Sweden.

SUBJECTS

A total of 5452 healthy men, 28-61 years of age.

MAIN OUTCOME MEASURES

Incidence of first coronary events was monitored over a mean follow-up of 19 years. The fatality of the future events was studied in relation to FEV and FVC.

RESULTS

A total of 589 men suffered a coronary event during follow-up, 165 of them were fatal during the first day. After risk factors adjustment, low FEV or FVC were associated with incidence of coronary events (fatal or nonfatal) and this relationship was most pronounced for the fatal events. Amongst men who subsequently had a coronary event, the case-fatality rates were higher in men with low FEV or FVC. Adjusted for risk factors, the odds ratio for death during the first day was 1.00 (reference), 1.63 (95% CI: 0.9-3.1), 1.86 (1.0-3.5) and 2.06 (1.1-3.9), respectively, for men with FVC in the 4th, 3rd, 2nd, and lowest quartiles (trend: P < 0.05). FEV showed similar relationships with the fatality rates.

CONCLUSION

Apparently healthy men with moderately reduced lung function have higher fatality in future coronary events, with a higher proportion of coronary heart disease deaths and less nonfatal myocardial infarction.

Changes in practice patterns affecting in-hospital and post-discharge survival among ACS patients

Background

Adherence to clinical practice guidelines for the treatment of specific illnesses may result in unexpected outcomes, given that multiple therapies must often be given to patients with diverse medical conditions. Yet, few studies have presented empirical evidence that quality improvement (QI) programs both change practice by improving adherence to guidelines and improve patient outcomes under the conditions of actual practice. Thus, we focus on patient survival, following hospitalization for acute coronary syndrome in three successive patient cohorts from the same community hospitals, with a quality improvement intervention occurring between cohorts two and three.

Methods

This study is a comparison of three historical cohorts of Acute Coronary Syndrome (ACS) patients in the same five community hospitals in 1994–5, 1997, 2002–3. A quality improvement project, the Guidelines Applied to Practice (GAP), was implemented in these hospitals in 2001.

Study participants were recruited from community hospitals located in two Michigan communities during three separate time periods. The cohorts comprise (1) patients enrolled between December 1993 and April 1995 (N = 814), (2) patients enrolled between February 1997 and September 1997 (N = 452), and (3) patients enrolled between January 14, 2002 and April 13, 2003 (N = 710).

Mortality data were obtained from Michigan's Bureau of Vital Statistics for all three patient cohorts. Predictor variables, obtained from medical record reviews, included demographic information, indicators of disease severity (ejection fraction), co-morbid conditions, hospital treatment information concerning most invasive procedures and the use of ace-inhibitors, beta-blockers and aspirin in the hospital and as discharge recommendations.

Results

Adjusted in-hospital mortality showed a marked improvement with a HR = 0.16 (p < 0.001) comparing 2003 patients in the same hospitals to those 10 years earlier. Large gains in the in-hospital mortality were maintained based on 1-year mortality rates after hospital discharge.

Conclusion

Changes in practice patterns that follow recommended guidelines can significantly improve care for ACS patients. In-hospital mortality gains were maintained in the year following discharge.

Time-varying risk factors for long-term mortality after coronary artery bypass graft surgery

BACKGROUND

There is a substantial literature on short-term mortality risk factors for coronary artery bypass graft (CABG) surgery. However, very few studies have examined risk factors for long-term mortality.

METHODS

We analyzed 56,543 veterans who underwent CABG surgery at one of 43 VA cardiac surgery centers between October 1, 1991, and March 30, 2001. Each patient was followed for a minimum of 3.5 months and a maximum of 9.5 years for mortality assessment. The time-varying effects of 22 mortality preoperative risk factors were evaluated using both standard Cox regression models and Cox B-spline regression models.

RESULTS

Six variables showed significant varying effects over time on mortality after surgery. The effects of previous heart surgery or preoperative intra-aortic balloon pump carried about 5 times and 3 times the risk, respectively, of dying on the first day after surgery, but were not significant during long-term follow-up. Conversely, diabetes had little additional risk immediately after surgery, but the risk increased steadily and doubled at 9.5 years after surgery. Three other risk variables--age, chronic obstructive pulmonary disease, and urgent or emergent status--also had risk changing by 50% to 60% over the next decade. Most of the other 16 risk variables were significantly associated with mortality, but the risk did not vary substantially over time.

CONCLUSIONS

Risk associated with some preoperative variables can change significantly during the decade after surgery, and risk assessments that assume constant risk during the postoperative period may substantially overestimate or underestimate risk at some times. These findings may help clinicians identify appropriate management strategies for patients during the years after CABG surgery, and support an emphasis on noncardiac comorbidities during later postoperative periods.

The importance of independent risk-factors for long-term mortality prediction after cardiac surgery

The purpose of the present study was to determine independent predictors for long-term mortality after cardiac surgery. The European System for Cardiac Operative Risk Evaluation (EuroSCORE) was developed to score in-hospital mortality and recent studies have shown its ability to predict long-term mortality as well. We compared forecasts based on EuroSCORE with other models based on independent predictors. Medical records of patients with cardiac surgery who were discharged alive (n = 4852) were retrospectively reviewed. Their operative surgical risks were calculated according to EuroSCORE. Patients were randomly divided into two groups: training dataset (n = 3233) and validation dataset (n = 1619). Long-term survival data (mean follow-up 5.1 years) were obtained from the National Death Index. We compared four models: standard EuroSCORE (M1); logistic EuroSCORE (M2); M2 and other preoperative, intra-operative and post-operative selected variables (M3); and selected variables only (M4). M3 and M4 were determined with multivariable Cox regression analysis using the training dataset. The estimated five-year survival rates of the quartiles in compared models in the validation dataset were: 94.5%, 87.8%, 77.1%, 64.9% for M1; 95.1%, 88.0%, 80.5%, 64.4% for M2; 93.4%, 89.4%, 80.8%, 64.1% for M3; and 95.8%, 90.9%, 81.0%, 59.9% for M4. In the four models, the odds of death in the highest-risk quartile was 8.4-, 8.5-, 9.4- and 15.6-fold higher, respectively, than the odds of death in the lowest-risk quartile (P < 0.0001 for all). EuroSCORE is a good predictor of long-term mortality after cardiac surgery. We developed and validated a model using selected preoperative, intra-operative and post-operative variables that has better discriminatory ability.

Renal dysfunction increases the risk of saphenous vein graft occlusion: results from the Post-CABG trial

OBJECTIVES

Saphenous vein grafts are common among patients with a history of coronary artery bypass graft (CABG) surgery. Chronic kidney disease (CKD) is an established cardiovascular risk factor, but its role in graft disease has not been evaluated.

METHODS AND RESULTS

The Post-CABG Trial randomized 1351 patients who had undergone CABG surgery 1-11 years earlier to high- or low-dose lovastatin and to low-dose warfarin or placebo. Coronary angiography was conducted at baseline and after a median follow-up time of 4.2 years. Subjects were grouped according to their baseline estimated glomerular filtration rate (eGFR). The primary trial endpoint was significant graft disease progression assessed angiographically. Additional pre-defined endpoints included occlusion of grafts patent at baseline, change in minimum lumen diameter, and a composite endpoint of recurrent clinical events. Decreasing eGFR was associated with an increased risk of graft occlusion (P(trend)=0.040), but not substantial atherosclerotic progression (P(trend)=0.30), per-graft change in minimum lumen diameter (P(trend)=0.067), or recurrent clinical events (P(trend)=0.86). We did not observe significant effect modification of treatment effects by the presence of CKD.

CONCLUSIONS

CKD may be associated with increased risk of atherosclerotic plaque disruption rather than atherosclerotic progression in saphenous vein grafts.

Long-Term Survival of Patients With Chronic Obstructive Pulmonary Disease Undergoing Coronary Artery Bypass Surgery

Background— Chronic obstructive pulmonary disease (COPD) is associated with increased in-hospital mortality in patients undergoing coronary artery bypass surgery (CABG). Long-term survival is less well understood. The present study examined the effect of COPD on survival after CABG.

Methods and Results— We conducted a prospective study of 33 137 consecutive isolated CABG patients between 1992 and 2001 in northern New England. Records were linked to the National Death Index for long-term mortality data. Cox proportional hazards regression was used to calculate hazard ratios (HRs). Patients were stratified by: no comorbidities (none), COPD, COPD plus comorbidities, and other comorbidities with no COPD. There were 131 434 person years of follow-up and 5344 deaths. The overall incidence rate (deaths per 100 person years) was 4.1. By group, rates were: 2.1 (none), 4.0 (COPD alone), 5.5 (other), and 9.4 (COPD plus; log rank P <0.001). After adjustment, survival with COPD alone was worse compared with none (HR, 1.8; 95% CI, 1.6 to 2.1; P <0.001). Patients with other comorbidities compared with none had even worse survival (HR, 2.2; 95% CI, 2.1 to 2.4; P <0.001). Patients with COPD plus other comorbidities compared with none had the worst long-term survival (HR, 3.6; 95% CI, 3.3 to 3.9; P <0.001).

Conclusions— Patients with only COPD had significantly reduced long-term survival compared with patient with no comorbidities. Patients with COPD and ≥1 other comorbidity had the worst survival rate when compared with all of the other groups.

Prolonged Intensive Care Unit Stay in Cardiac Surgery: Risk Factors and Long-Term-Survival

BACKGROUND

Risk factors have been found for prolonged intensive care unit (ICU) stay in cardiac surgery patients in only a few studies; conflicting results have been described. The focus of this study was twofold: first, to evaluate preoperative, intraoperative, and postoperative risk factors for ICU stay greater than 3 days in a cardiac surgery patient population; second, to evaluate long-term survival in cardiac surgery patients with prolonged ICU stay.

METHODS

Records from 2,683 cardiac surgery patients were retrospectively evaluated. Univariate and multivariate analyses for risk factors were performed for an ICU stay greater than 3 days. Thereafter, 2,563 patients were enrolled in a follow-up study for an observational time of 3 years after surgery.

RESULTS

Mortality was dependent on renal, respiratory, and heart failure, as well as age, elevated APACHE II scores, and reexploration. Long-term survival analyses demonstrated a significantly lower survival in patients with longer ICU stay. However, the 6-month to 3-year long-term survival was comparable with survival in patients without prolonged ICU stay.

CONCLUSIONS

Because of the increasing acuity of patients needing cardiac surgery, it is important to identify those at risk for a prolonged ICU course. It is therefore of paramount interest to implement measures throughout their entire hospital stay that would maximize organ function to improve survival and resource utilization.

Subclinical Peripheral Arterial Disease and Incompressible Ankle Arteries Are Both Long-Term Prognostic Factors in Patients Undergoing Coronary Artery Bypass Grafting

OBJECTIVES

This study was designed to determine the prevalence of peripheral arterial disease (PAD) in candidates for coronary artery bypass grafting (CABG) and to assess the predictive value of different types of subclinical PAD (peripheral occlusive disease and medial arterial calcification [incompressible ankle arteries]).

BACKGROUND

Observational studies report poor prognosis after CABG in the presence of clinical PAD, but data on subclinical PAD are scarce.

METHODS

We prospectively enrolled CABG candidates and measured ankle-brachial index (ABI) preoperatively. Patients were divided into four groups: clinical PAD, subclinical PAD (ABI <0.85), incompressible arteries (ABI >1.5), and no PAD. The primary end point was a composite combining death, acute coronary syndrome, stroke or transient ischemic attack (TIA), and coronary or peripheral revascularization. Secondary end points were overall and cardiovascular death, acute coronary syndrome, and stroke or TIA. Statistical analyses were performed using the Cox regression model.

RESULTS

We consecutively enrolled 1,022 patients (mean age 66.9 +/- 9.2 years). In addition to the 14% with clinical PAD, we detected subclinical PAD in 13% and medial artery calcification in 12%. During an actuarial follow-up of 4.4 years, 81.2% of patients remained event-free. Adverse factors were (p < 0.05) supraventricular arrhythmia (odds ratio [OR] 2.5), ejection fraction <0.40 (OR 2.3), combined valvular surgery (OR 2.5), clinical PAD (OR 3.6), subclinical PAD (OR 3.3), and medial artery calcification (OR 1.9). The latter three factors were also independently predictive for overall and cardiovascular death.

CONCLUSIONS

Beyond clinical PAD, the measurement of ABI before coronary surgery provides substantial information on long-term postoperative prognosis. To our knowledge, this is the first study highlighting the prognostic role of incompressible ankle arteries in secondary prevention.

Impact of renal insufficiency on short- and long-term outcomes after cardiac surgery

BACKGROUND

Renal insufficiency is highly prevalent in North America and has been established as a nontraditional risk factor for cardiovascular disease. Cardiovascular disease remains the primary cause of mortality in the general population and is often treated with coronary artery bypass surgery (CABG). This population-based study aimed to determine the risk of nondialysis dependent renal insufficiency (RI) on the long-term outcomes of patients who undergo CABG.

METHODS

Prospectively collected data from 26,506 patients were abstracted from the Cardiac Care Network database from 9 revascularization hospitals in Ontario, Canada. Multivariate regression analysis examined associations between preoperative RI and inhospital, 30-day, and 1-year mortality according to 3 levels of serum creatinine: <120 micromol/L (normal), 120 to 180 micromol/L (mild RI), and >180 micromil/L (moderate-severe RI) and 5 levels of creatinine clearance (Cockcroft-Gault): >100 mL/min (normal), 80 to 99 mL/min (mild impairment), 60 to 79 mL/min (mild-moderate impairment), 40 to 59 mL/min (moderate impairment), and <40 mL/min (severe impairment).

RESULTS

The overall inhospital, 30-day, and 1-year mortality rates were 1.90%, 2.0%, and 4.5%, respectively. Patients with RI had greater overall comorbidity. After adjustment for confounding factors, RI was associated with the greater risk of both 30-day (odds ratio 3.7, 95% CI 2.3-5.8, P <.0001) and 1-year mortality (odds ratio 4.6, 95% CI 3.3-6.4, P <.0001).

CONCLUSION

Preoperative renal impairment should be recognized as a significant risk factor for mortality after CABG. A trend of increasing risk with severity of renal impairment was demonstrated for both 30-day and 1-year mortality in this large, population-based study.

Effect of chronic obstructive pulmonary disease on survival of patients with coronary heart disease having percutaneous coronary intervention

There are limited data regarding the effect of chronic obstructive pulmonary disease (COPD) on the survival of patients with coronary artery disease. Prospectively developed and collected data elements on 4,284 consecutive patients who underwent percutaneous coronary intervention in 3 hospitals in 1998 and 1999 were pooled and analyzed. In-hospital major adverse cardiac outcomes were not different between groups. At 3-year follow-up, mortality for patients with COPD was 21% versus 9% for patients without COPD (log-rank p < 0.001). COPD was independently associated with a 2-fold increase in the hazard of long-term mortality (hazard ratio 2.146, 95% confidence interval 1.525 to 3.021, p < 0.001).

Relation between depressive symptoms and treadmill exercise capacity in the Heart and Soul Study

To examine the association between depressive symptoms and exercise capacity, we performed a cross-sectional study of 944 outpatients with stable coronary artery disease and found that the presence of depressive symptoms was independently associated with poor exercise capacity (<5 MET tasks achieved; adjusted odds ratio 1.8, 95% confidence interval 1.1 to 2.7, p = 0.01). Depressive symptoms should be considered in the differential diagnosis of poor exercise capacity.

[Value of gated-SPECT in defining the post-revascularization prognosis of patients with ischemic cardiomyopathy]

INTRODUCTION AND OBJECTIVES

Gated-SPECT simultaneously evaluates perfusion and ventricular function and could provide important prognostic information in ischemic cardiomyopathy. Our aim was to study the value of gated-SPECT performed before revascularization in a cardioischemic population to predict the outcome of revascularization.

METHODS

One hundred and ten patients who had undergone percutaneous (n = 100) or surgical revascularization were included. Patients underwent sestamibi gated-SPECT before revascularization. After revascularization, they were followed-up for at least 12 months (mean 23.7 months, maximum 44 months). We recorded deaths and a combined clinical event of death, non-fatal infarction, and hospital re-admission for cardiac reasons. We analyzed the prognostic value of clinical, angiographic, and gated-SPECT variables.

RESULTS

During follow-up, there were 14 deaths (6.4%/ year) and 36 cases of combined events (16.5%/year). Multivariate analysis showed that depressed gated-SPECT ejection fraction (threshold 0.30) was the only variable independently related to death (OR = 4.8; 95%CI, 1.6-14.6) and combined event (OR = 2.5; 95%CI, 1.2-4.8). Survival analysis showed that patients with ejection fraction < or = 0.30% had a significantly shorter period of time free of death (33 months [28-38] versus 42 months [40-44]; p = 0.002) and combined events (28 months [23-32] versus 36 months [33-39]; p = 0.007).

CONCLUSIONS

Gated-SPECT, due to the information it provides about left ventricular function, predicts the prognosis of patients after coronary revascularization.

Variation in mortality risk factors with time after coronary artery bypass graft operation

BACKGROUND

Differences in mortality risk factor sets during different time periods (eg, short-term versus intermediate-term) after coronary artery bypass grafting have been reported. However, little is known about the time-varying effects of mortality risk factors after the operation.

METHODS

We analyzed 11,815 veterans who had coronary artery bypass grafting at any of the 43 Veterans Affairs cardiac surgery centers from October 1997 to September 1999. Time-varying effects of 14 mortality risk factors during the 210 days after coronary artery bypass grafting were evaluated using Cox B-spline regression, which provides an estimate of risk for each variable for each day after operation.

RESULTS

Eight variables showed significant time-varying effects after operation. The effect of prior heart operation was very high immediately after operation, but disappeared within 1 week. Three other cardiac variables (prior myocardial infarction, preoperative intraaortic balloon pump, and Canadian Cardiovascular Society anginal class III or IV) also conferred the highest risk on the day of operation and decreased thereafter. In contrast, the four time-varying noncardiac risk variables (age, impaired functional status, chronic obstructive pulmonary disease, and renal dysfunction) showed little or no association with mortality immediately after operation, but had increasing impact during the several months after operation.

CONCLUSIONS

A sizable number of mortality risk factors have time-varying effects after coronary artery bypass grafting. Several cardiac risk factors have peak impact immediately after operation but dissipate thereafter. Several noncardiac risk factors confer little risk immediately after operation, but these risks increase during several months. This information may help clinicians focus management strategies for patients during the 7 months after operation.

Outcome of cardiac surgery patients with complicated intensive care unit stay

Risk stratification has become an essential element in the practice of cardiac surgery. Several studies have identified preoperative risk factors for adverse outcome. However, outcome is mostly defined by 30-day mortality and morbidity. These data reflect poorly the benefit for the patient. Long-term survival, quality of life, and functional status should be included in a more global analysis of the outcome, particularly in patients with complicated ICU stay. By reviewing the recent data reported in the literature, we can identify a number of preoperative predictive factors for complicated ICU stay, including advanced age, chronic obstructive pulmonary disease, preoperative low ejection fraction, previous myocardial infarction, reoperation, renal failure, combined surgery (coronary artery bypass grafting plus valve surgery), low hematocrit, and neurologic impairment. Short- and long-term outcomes are dependent on the type of postoperative complication. Unfortunately, data regarding the long-term outcome in these situations are very scarce.

Revascularization during acute myocardial infarction: risks and benefits revisited

BACKGROUND

Indication for immediate revascularization during acute myocardial infarction (MI) is debated. Drug-resistant crescendo angina, as well as hemodynamic compromise, however, often requires acute operation. In this study the differential risks of acute coronary artery bypass grafting with and without MI were stratified.

METHODS

Five hundred eighteen patients undergoing isolated coronary artery bypass grafting were investigated. Thirty-nine patients underwent acute revascularization because of enzyme-proven or electrocardiogram-proven MI accompanied by crescendo angina, hemodynamic compromise, or both. They were compared with 33 emergent, 63 urgent, and 383 elective patients without MI. Preoperative risk factors for early mortality and necessity of continuous venovenous hemofiltration were analyzed by means of logistical regression analysis. Perioperative data were compared.

RESULTS

Early mortality of the MI cohort was 15.4%, in contrast to 15.2% in emergent, none in urgent, and 2.1% in elective patients. Left internal thoracic artery was used in 87% of MI, 97% of emergent, 94% of urgent, and 97% of elective patients. Intraaortic balloon pump was necessary in 50% of MI patients, 27% of emergent, 6.3% of urgent, and 3.1% of elective cases. Continuous venovenous hemofiltration was performed in 29% of MI patients, 15% of emergent, 4.9% of urgent, and 3.4% of elective patients. Hemodynamic instability significantly increased the odds ratio for early mortality and continuous venovenous hemofiltration.

CONCLUSIONS

Patients undergoing acute revascularization carried an elevated risk to die early notwithstanding the presence or absence of acute MI. Liberal use of left internal thoracic artery grafts was not detrimental in acute patients whereas liberal use of intraaortic balloon pump was beneficial. In almost 30% of MI patients, continuous venovenous hemofiltration was not necessary, implying a severely impaired perioperative hemodynamic condition. Immediate revascularization in the presence of acute MI is therefore indicated although it may be addressed as a separate high-risk group.