Likely variations in perioperative mortality associated with cardiac surgery: when does high mortality reflect bad practice?

OBJECTIVE—Several methods exist for estimating the risk of perioperative mortality based on preoperative risk factors; graphical methods such as the variable life adjusted display (VLAD) can be used to examine how an individual surgeon's performance for a series of operations fares against what would be expected, given the case mix. This study aimed to devise a method for assessing the natural variation in outcome in order to assist with making judgements about individual performance, in particular whether seemingly poor performance could have occurred by chance.
METHOD—The risk scoring system has been derived and validated locally for cardiac surgery. A method is described for calculating the probability that an observed number of deaths occurs within a sequence of operations if perioperative mortality is regarded as a chance event with an expected value derived from the risk score. To illustrate this method, nested prediction intervals are superimposed onto VLAD plots for a series of 393 isolated coronary artery bypass and isolated valve operations performed by a single surgeon.
RESULTS—Using the locally derived risk score, the VLAD plot for the individual surgeon shows a net life gain of about 6 over the predicted number of survivors, which is observed to be within the 90% prediction interval. If the Parsonnet scoring system is used instead of the locally derived risk score, the net life gain is considerably overestimated.
CONCLUSIONS—The nested prediction intervals are straightforward to generate and can be integrated into a visually informative display. As an indication of the inherent variability in outcome, they have a valuable role in the monitoring of surgical performance.


Keywords: perioperative mortality; variable life adjusted display; locally derived risk score; Parsonnet score     

Mucopolysaccharidosis I under enzyme replacement therapy with laronidase—A mortality case with autopsy report

There is little information about MPS I-related complications during laronidase therapy. We describe the first autopsy report of a young male MPS I patient who died of infection-induced cardiopulmonary failure following 2 years of weekly treatment with laronidase.     

Do symptoms predict cardiac arrhythmias and mortality in patients with syncope?

BACKGROUND: Patients with syncope frequently present with multitude of other symptoms but their significance in predicting morbidity or mortality has not been previously studied. OBJECTIVE: To determine if certain symptoms can be used to identify syncope patients at risk for cardiac arrhythmias, mortality, or recurrence of syncope. PATIENTS AND METHODS: From August 1987 to February 1991, we prospectively evaluated patients with syncope from outpatient, inpatient, and emergency department services of a university medical center. These patients were interviewed, charts were reviewed, and detailed information on 19 symptoms and comorbidities was obtained. A cause of syncope was assigned using standardized diagnostic criteria. All patients were followed up at 3-month intervals for at least 1 year for recurrence of syncope and mortality. Patients in whom the cause of syncope was determined by medical history and physical examination alone were not included in our analysis. RESULTS: History and physical examination led to the cause of syncope in 222 of 497 patients enrolled. In the remaining 275 patients, the absence of nausea and vomiting before syncope (odds ratio, 7.1) and electrocardiographic abnormalities (odds ratio, 23.5) were predictors of arrhythmic syncope. Underlying cardiac disease was the only predictor of 1-year mortality. No symptom remained as independent predictor for 1-year mortality or syncope recurrence. CONCLUSIONS: Symptoms, although important in assigning many noncardiac causes, are not useful in risk-stratifying patients whose cause of syncope cannot be identified by other history and physical examination. Triage decisions and management plans should be based on pre-existing cardiac disease or electrocardiographic abnormalities, which are important predictors of arrhythmic syncope and mortality.     

Tumor necrosis factor-α and mortality in patients infected with Vibrio vulnificus

Serum tumor necrosis factor-α (TNF-α) was evaluated in Vibrio vulnificus-infected patients at admission. The median TNF-α concentration in the non-survivor group was determined to be 261.0 pg/mL, in contrast to 69.5 pg/mL in the survivor group (P = 0.001). Hence, serum TNF-α concentration may potentially be an early predictor of the mortality in patients with Vibrio septicemia.     

Comment on “Association of coffee drinking with total and cause-specific mortality”

Background: Coffee is one of the most widely consumed beverages, but the association between coffee consumption and the risk of death remains unclear.Methods: We examined the association of coffee drinking with subsequent total and cause-specific mortality among 229 119 men and 173 141 women in the National Institutes of Health – AARP Diet and Health Study who were 50–71 years of age at baseline. Participants with cancer, heart disease, and stroke were excluded. Coffee consumption was assessed once at baseline.Results: During 5 148 760 person-years of follow-up between 1995 and 2008, a total of 33 731 men and 18 784 women died. In age-adjusted models, the risk of death was increased among coffee drinkers. However, coffee drinkers were also more likely to smoke, and, after adjustment for tobacco-smoking status and other potential confounders, there was a significant inverse association between coffee consumption and mortality. Adjusted hazard ratios for death among men who drank coffee as compared with those who did not were as follows: 0.99 (95% confidence interval [CI], 0.95 to 1.04) for drinking less than 1 cup per day, 0.94 (95% CI, 0.90 to 0.99) for 1 cup, 0.90 (95% CI, 0.86 to 0.93) for 2 or 3 cups, 0.88 (95% CI, 0.84 to 0.93) for 4 or 5 cups, and 0.90 (95% CI, 0.85 to 0.96) for 6 or more cups of coffee per day (P < 0.001 for trend); the respective hazard ratios among women were 1.01 (95% CI, 0.96 to 1.07), 0.95 (95% CI, 0.90 to 1.01), 0.87 (95% CI, 0.83 to 0.92), 0.84 (95% CI, 0.79 to 0.90), and 0.85 (95% CI, 0.78 to 0.93) (p < 0.001 for trend). Inverse associations were observed for deaths due to heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections, but not for deaths due to cancer. Results were similar in subgroups, including persons who had never smoked and persons who reported very good to excellent health at baseline.Conclusions: In this large prospective study, coffee consumption was inversely associated with total and cause-specific mortality. Whether this was a causal or associational finding cannot be determined from our data.

Comment

Coffee is the most widely used stimulant beverage in the world. Caffeine is the active substance of coffee and belongs to the methylxanthine pharmacological group.Coffee is a complex mixture of thousands of chemical components, including carbohydrates, nitrogenates, lipids, minerals, vitamins, alkaloids and phenols.Due to its widespread consumption, coffee constitutes a major concern for many people, and, it must be admitted, does not have a good reputation: some of my students, when presenting a case at the bedside, include coffee alongside smoking as a major cardiovascular risk factor.This myth – because it really is a myth – is very hard to contradict, even though there are many studies showing that coffee prevents type 2 diabetes mellitus,¹ dementia,² Parkinson's disease³ and liver cancer.⁴ With regard to cardiovascular disease, coffee seems to have very little effect on normal individuals but may slightly increase blood pressure in hypertensive patients⁵, and probably increases atrial fibrillation incidence⁶.The present study⁷ looks at the relationship between coffee intake and subsequent total and cause-specific mortality among 229 119 men and 173 141 women in the National Institutes of Health AARP Diet and Health Study. Analyzing a total of 5 148 760 person-years of follow-up between 1995 and 2008, the author found that the risk of death was increased among coffee drinkers but, after adjustment for tobacco-smoking status and other potential confounders, there was a significant inverse association between coffee consumption and mortality, with hazard ratios between 1.01 and 0.84, i.e. ranging from a small increase of 0.1% to a decrease of 16%. Inverse associations were observed for deaths due to heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections, but not for deaths due to cancer.This study, by showing that coffee consumption was inversely associated with total and cause-specific mortality, should put to rest fears about this beverage, which, like anything else, should be taken in moderation.

Conflicts of interest

The author has no conflict of interest to declare.