Admission serum potassium in patients with acute myocardial infarction - Its correlates and value as a determinant of in-hospital outcome
Admission serum potassium in patients with acute myocardial infarction - Its correlates and value as a determinant of in-hospital outcome
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DOI：
10.1378/chest.118.4.904
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发表时间：
2000-10-01
期刊：
影响因子：
9.6
通讯作者：
Madias, NE
中科院分区：
文献类型：
--
作者：
Madias, JE;Shah, B;Madias, NE
研究目的：尽管存在争议，但认为急性心肌梗死（MI）患者的低钾血症（LK）可预测院内发病率（尤其是心律失常）和死亡率的增加。此外，心肌梗死时低血清钾的机制尚未阐明。我们评估的频率，属性和结果，并推测LK在MI. Design患者的机制：这是一个前瞻性的横断面研究517例连续MI患者入住冠状动脉监护病房（CCU）。血清钾测定在急诊科，并反复此后在整个住院期间，并被用于分析，沿着一个大阵列的临床和实验室variables. Results：患者被分配到一个LK和正常血钾（NK）队列，根据急诊科血清钾测量。41例LK患者（3.16 +/-0.24 mEq/L;占总数的7.9%）在入院时的基线评估与476例血清钾正常的患者相当（4.28 +/-0.56 mEq/L），急诊室镁较低除外（1.48 +/-0.15 mg/dL vs 1.96 +/-0.26 mg/dL; p = 0.0005）和症状发作后更早出现（3.0 +/-4.1 h vs 1.4 +/-6.2 h; p = 0.05）。入院时血清钾和镁之间的相关性较差（r = 0.14）。LR患者的肌酸激酶（CK）峰值和心肌CK异构体较高（分别为3，870 +/-3，810 IU/L vs 2，359 +/-2，653 IU/L [p = 0.018]和358 +/-312 IU/L vs 228 +/-258 IU/L [p 0.013]）。两个队列的管理是相同的，除了LK患者中镁（14.6% vs 4.6%; p = 0.007）、血清钾补充剂（80.2% vs 43.1%; p = 0.00005）和抗肿瘤药物（78.0% vs 50.4%; p = 0.0007）的使用率更高。LK和NK患者的总死亡率无差异（24.4% vs 18.3%; p = 0.31），心源性死亡（17.1% vs 15.3%; p = 0.52），房颤（14.6% vs 13.9%; p = 0.89），室性心动过速（22.0% vs 16.0%; p = 0.32），但室颤（VF）在LK患者中更常见（24.4% vs 13.0%; p = 0.04）。然而，两个队列中急诊科、CCU或病房发生VF的比例没有差异，但LK患者在急诊科入院前的时间间隔内发生VF的比例较高（17.1%vs2.1%，p = 0.00001）结论：在急诊室的MI患者中约有8%可见LK; LK与急诊室低镁、CCU和整个住院期间低血清钾水平相关。LK与入院前使用利尿剂无关，与早期急诊相关，但不是发病率或死亡率增加的预测因子。
Study objectives: Although controversial, hypokalemia (LK) in patients with acute myocardial infarction (MI) is thought to predict increased in-hospital morbidity, particularly cardiac arrhythmias, and mortality. Also, the mechanism of low serum potassium in the setting of MI has not been delineated. We evaluated the frequency, attributes, and outcome, and speculated on the mechanism of LK in patients with MI.Design: This was a prospective cross-sectional study of 517 consecutive patients with MI admitted to the coronary care unit (CCU). Serum potassium was measured in the emergency department and repeatedly thereafter throughout hospitalization, and was used in the analysis, along with a large array of clinical and laboratory variables.Results: The patients were allocated to a LK and a normokalemic (NK) cohort, based on the emergency department serum potassium measurement. The 41 patients with LK (3.16 +/- 0.24 mEq/L; 7.9% of total) were comparable on admission in their baseline assessment to the 476 patients with normal serum potassium (4.28 +/- 0.56 mEq/L), except for lower emergency department magnesium (1.48 +/- 0.15 mg/dL vs 1.96 +/- 0.26 mg/dL; p = 0.0005) and earlier presentation after onset of symptoms (3.0 +/- 4.1 h vs 1.4 +/- 6.2 h; p = 0.05). There was a poor correlation between serum potassium and magnesium on admission (r = 0.14). Peak creatine kinase (CK) and myocardial isomer of CK were higher in the LR patients (3,870 +/- 3,810 IU/L vs 2,359 +/- 2,653 IU/L [p = 0.018] and 358 +/- 312 IU/L vs 228 +/- 258 IU/L [p 0.013], respectively). Management of the two cohorts was the same, except for a higher rate of use of magnesium (14.6% vs 4.6%; p = 0.007), serum potassium supplements (80.2% vs 43.1%; p = 0.000005), and antiarrhythmic drugs (78.0% vs 50.4%; p = 0.0007) in the LK patients. No difference was detected between the LK and NK patients in total mortality (24.4% vs 18.3%; p = 0.31), cardiac mortality (17.1% vs 15.3%; p = 0.52), atrial fibrillation (14.6% vs 13.9%; p = 0.89), and ventricular tachycardia (22.0% vs 16.0%; p = 0.32), but ventricular fibrillation (VF) occurred more often (24.4% vs 13.0%; p = 0.04) in the LK patients. However, proportions of VF occurring in the emergency department, CCU, or wards in the two cohorts were not different, but they were higher during the time interval prior to emergency department admission in LK patients (17.1% vs 2.1%; p = 0.00001).Conclusions: LK is seen in approximately 8% of patients with MI in the emergency department; LK is associated with low emergency department magnesium, and low serum potassium levels in the CCU and throughout hospitalization. LK has no relationship to preadmission use of diuretics, it is associated with early presentation to the emergency department, and it is not a predictor of increased morbidity or mortality.