Prolonged QT interval in ST-elevation myocardial infarction and mortality: new prognostic scale with QT, Killip and age.

AIMS: To analyze the relation between prolonged QT interval and mortality in patients with ST-elevation myocardial infarction and complementarity with Killip, Thrombolysis in Myocardial Infarction (TIMI) and Acute Physiology and Chronic Health Evaluation-II (APACHE-II) scales. METHODS: A nested cohort case-control study was conducted in a Spanish hospital. The cohort consisted of patients with ST-elevation myocardial infarction admitted between 2008 and 2010 (n = 524). The cases were the patients who died (n = 38) and the controls (n = 81) were a random sample of those who survived (one of every six). RESULTS: The corrected QT (QTc) interval of first ECG (prehospital-or-hospital admission) was prolonged in 18 of the 35 patients who died (51.4%) and in 12 of the controls (16.7%; P < 0.001). APACHE-II, TIMI and Killip scores were higher in the patients who had died (P < 0.001). Mortality with prolonged QTc (19.3%) was 20%, and 4.5% were with normal QTc (80.7%; P < 0.001).Logistic regression showed a relation between mortality with prolonged QTc and TIMI [odds ratio (OR) 3.57(1.16-10.97)]. A second model was constructed with APACHE-II and prolonged QTc [OR 6.47(1.77-23.59)]; receiver operating characteristic (ROC) curve area [0.92(0.87-0.97)], and individually, for APACHE-II was 0.88 (0.81-0.95). A new score was constructed: QTc (not prolonged: 0 points, prolonged: 7 points), age (<65 years: 0 points, 65-74 years: 6 points, ≥75 years: 9 points), Killip (I: 0 points, II-III: 4 points, IV: 17 points). ROC area: 0.88. CONCLUSIONS: Hospital mortality was higher with prolonged QTc at prehospital-or-hospital admission, given equal Killip, TIMI and APACHE values. Discrimination of Killip, TIMI and APACHE values can be improved with prolonged QTc. Discrimination of a model including Killip, age and prolonged QTc is quite good. We have made a new simple prognostic scale with these variables.

Evaluation of prognostic scale Thrombolysis In Myocardial Infarction and Killip. An ST-elevation myocardial infarction new scale.

BACKGROUND: Prognostic systems are complex. So it is necessary to find tools, which are easy to use and have good calibration and discrimination. OBJECTIVES: The objective of this study is to evaluate the usefulness of Killip, Thrombolysis In Myocardial Infarction (TIMI), and age to develop a new prognostic scale for patients with ST-elevation myocardial infarction (STEMI). METHODS: The study population included all patients with STEMI consecutively admitted to the Intensive Care Unit of Carlos Haya Hospital, Malaga, Spain. Top variables included are Killip and TIMI, hospital mortality, intensive care unit stay, treatment received, and care times intervals. RESULTS: The results are 806 patients; 75.6% men; age 63.11 ± 12.83 years old; TIMI, 3.57 ± 2.38; Killip I, 81.4%; and hospital mortality, 11.3%. Mortality increased in relation to age, TIMI, and Killip (P < .001). Receiver operating characteristic (ROC) area for TIMI is 0.832 (0.786-0.878) and Killip, 0.757 (0.698-0.822). Thrombolysis In Myocardial Infarction classification was associated with Killip and age by multiple linear regression. Patients were stratified into 5 groups according to Killip and age: Killip I and younger than 65 years (n = 369; mortality, 1.4%; odds ratio [OR], 1), Killip I and 65 to 75 years old (n = 173; mortality, 6.9%; OR, 5.43 [1.88-15.66]), Killip I and older than 75 years (n = 112; mortality, 18.9%; OR, 13.03 [4.69-36.21]), Killip II to III (n = 129; mortality, 31%; OR, 22.72 [12.55-85.29]), Killip IV (n = 20; mortality, 80%; OR, 291.2 [71.32-1189]). ROC area is 0.84 (0.798-0.883). We created a scale with scores based on the ß coefficient of logistical regression. CONCLUSIONS: The TIMI scale discriminated hospital mortality correctly for STEMI. It performed better than Killip alone and similar to a simple model that included age and Killip. The 2-variable model consists of a simple scale with 5 categories.