Predictors of cardiogenic shock after thrombolytic therapy for acute myocardial infarction

OBJECTIVES: This study characterized clinical factors predictive of cardiogenic shock developing after thrombolytic therapy for acute myocardial infarction (AMI). BACKGROUND: Cardiogenic shock remains a common and ominous complication of AMI. By identifying patients at risk of developing shock, preventive measures may be implemented to avert its development. METHODS: We analyzed baseline variables associated with the development of shock after thrombolytic therapy in the Global Utilization of Streptikonase and Tissue-Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) trial. Using a Cox proportional hazards model, we devised a scoring system predicting the risk of shock. This model was then validated in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO-III) cohort. RESULTS: Shock developed in 1,889 patients a median of 11.6 h after enrollment. The major factors associated with increased adjusted risk of shock were age (chi2 = 285, hazard ratio [95% confidence interval] 1.47 [1.40, 1.53]), systolic blood pressure (chi2 = 280), heart rate (chi2 = 225) and Killip class (chi2 = 161, hazard ratio 1.70 [1.52, 1.90] and 2.95 [2.39, 3.63] for Killip II versus I and Killip III versus I, respectively) upon presentation. Together, these four variables accounted for >85% of the predictive information. These findings were transformed into an algorithm with a validated concordance index of 0.758. Applied to the GUSTO-III cohort, the four variables accounted for > 95% of the predictive information, and the validated concordance index was 0.796. CONCLUSIONS: A scoring system accurately predicts the risk of shock after thrombolytic therapy for AMI based primarily on the patient's age and physical examination on presentation.     

Growth hormone and pituitary radiotherapy, but not serum insulin-like growth factor-I concentrations, predict excess mortality in patients with acromegaly

Increased mortality in patients with acromegaly has been confirmed in a number of retrospective studies, but causative factors and relationship to serum IGF-I remain uncertain. The West Midlands Pituitary database contains details of 419 patients (241 female) with acromegaly. Serum IGF-I data from the Regional Endocrine Laboratory were available for 360 patients (86%). At diagnosis, mean age was 47 yr (range, 12-84) and mean duration of follow-up was 13 yr (0.5-48). Sixty-one percent were treated by surgery and 39% by nonsurgical means. Radiotherapy was used alone or as adjuvant therapy in 50%. All patients were registered with the Office of National Statistics to obtain information on deaths. At the date of analysis (31 December 2001), 95 of the 419 patients had died (43 males), giving a standardized mortality ratio of 1.26 [confidence interval (CI), 1.03-1.54; P = 0.046]. After controlling for age and sex, data indicated that mortality was increased in subjects with posttreatment GH levels more than 2 micro g/liter, compared with those with levels less than 2 micro g/liter [ratio of mortality rates (RR), 1.55 (range, 0.97-2.50); P = 0.068]. By contrast, a much smaller increase was observed for subjects with elevated posttreatment IGF-I levels compared with those with normal levels [RR, 1.20 (range, 0.71-2.03); P = 0.50]. Treatment with radiotherapy was associated with increased mortality [RR, 1.67 (range, 1.09-2.56); P = 0.018], with cerebrovascular disease the predominant cause of death [standardized mortality ratio, 4.42 (range, 2.71-7.22); P = 0.005]. These results confirm the increased mortality in acromegaly and suggest that reduction of GH levels to less than 2 micro g/liter is beneficial in terms of improving long-term outcome. The sole use of IGF-I as a marker for effective treatment of acromegaly is not justified by this data. This study also highlights the potential deleterious effect of radiotherapy.     

Occult popliteal artery stenosis masquerading as atheroemboli in a patient with previous knee replacement.

The purpose of this article is to report the unusual presentation of a 63-year-old patient with Rutherford grade 2, category 5 tissue ischemic changes involving the right foot secondary to an occult popliteal stenosis that was obscured behind a prosthetic knee on diagnostic angiograms. Conventional abdominal angiography with bilateral lower extremity runoff showed no evidence of significant disease and the patient was misdiagnosed with atheroemboli syndrome secondary to ipsilateral common femoral access following recent catheterization. Ultimately, a meticulous physical examination disclosed a bruit in the right popliteal fossa and selective right leg angiography with oblique views confirmed eccentric complex luminal encroachment in the right popliteal artery that was eclipsed by a prosthetic knee on antecedent nonselective angiography. The lesion responded favorably to endovascular treatment with durable clinical improvement. This case illustrates the importance of a meticulous physical examination and noninvasive studies prior to angiography in patients with ischemic tissue changes and emphasizes the importance of oblique views to image any vessel that may be obscured by a metal prosthesis.