The use of patient mix-adjusted control charts to compare in-hospital costs of care.

We introduce a technique for patient mix-adjusting x charts and compared differences between unadjusted and patient mix-adjusted results. Our data came from coronary artery bypass graft (CABG) surgery patients at Baptist Medical Center, Oklahoma City, Oklahoma. We first developed an unadjusted x control chart to compare monthly changes in CABG surgery costs and then used a published model to patient mix-adjust our x control chart information. Before adjustment, the average log costs for three of ten months were outside the 90% control limit lines, and there was a trend toward increasing costs. After adjustment, two months had average costs outside the 90% lower control limit lines, and the trend toward increasing costs had been explained by differences in patient acuity.

A randomized factorial trial of reperfusion strategies and aspirin dosing in acute myocardial infarction. The DUCCS-II Investigators.

The focus of new research efforts to improve the morbidity and mortality associated with acute myocardial infarction (AMI) has turned to adjuvant agents that show promise of improving outcomes following coronary thrombolysis. We enrolled 162 patients with AMI in a randomized trial comparing front-loaded tissue-plasminogen activator (t-PA) plus weight-adjusted heparin with anisoylated plasminogen streptokinase activator complex (APSAC) without heparin as well as standard-dose (325 mg) and low-dose (81 mg) aspirin. The primary end point was an in-hospital morbidity profile; secondary end points were clinical and angiographic potency and hemorrhagic events. Selected sites performed an electrocardiographic substudy to determine the time to 50% ST-segment recovery and the time to steady state. Although the trial was terminated when the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries-I trial showed that t-PA had a significant mortality advantage over streptokinase, important trends were evident. Patients given t-PA and heparin were better anticoagulated (p = 0.001), yet AP-SAC-treated patients had more bleeding complications. The primary end point favored t-PA (25.4% vs 31.3%), and the secondary end points were similar in both groups. In the electrocardiographic substudy, the t-PA group achieved both 50% ST-segment recovery and steady-state recovery sooner than the APSAC group. Patients taking low-dose aspirin had lower in-hospital mortality and less recurrent ischemia but more strokes than the standard-dose aspirin group. Thus, this trial demonstrated trends favoring front-loaded t-PA with weight-adjusted heparin over APSAC without heparin in the treatment of AMI. The use of low-dose aspirin did not appear to impose a loss of protection from adverse events, nor did standard-dose aspirin increase serious bleeding.

Diagnostic and prognostic significance of electrocardiographic and CPK isoenzyme changes following coronary bypass surgery: correlation with findings at one year.

The incidence of ECG (14 per cent) indication of acute myocardial infarction complicating coronary artery bypass surgery is documented, corroborating the findings of prior series. An additional 32 per cent of patients had appearance of myocardial specific CPK-MB in serum during the immediate postoperative period. All patients surviving to 1 year following surgery (93 of 103) were asked to return for repeat cardiac catheterization to determine the presence and extent of interim ventricular contraction abnormalities. Sixty-five (70 per cent) of the group returned for evaluation. Preoperative and 1 year postoperative left ventriculograms were compared to determine if new contraction abnormalities would confirm the specificity of perioperative QRS and isoenzyme changes, and if the absence of new abnormalities would confirm their sensitivity. The majority of patients (65 per cent) had new areas of asynergy. However, 73 per cent of these were confined to the apex and thus could have been produced by the vent employed during cardiopulmonary bypass. QRS changes were 100 per cent specific and CPK-MB appearance was 78 per cent specific but they were only 20 and 54 per cent sensitive, respectively. Indeed, 46 per cent of those with new asynergy which was non apical had neither QRS change nor CPK-MB appearance. Thus QRS changes were always--and CPK-MB appearance was usually--associated with new asynergy but, in addition, many patients with no perioperative indication of infarction developed new areas of left ventricular contraction abnormality within the first postoperative year.

The hemodynamic simulation of mitral regurgitation in ventricular septal defect after myocardial infarction.

The development of a ventricular septal defect (VSD) following myocardial infarction is an uncommon complication which clinically can be confused with mitral insufficiency due to infarction of a papillary muscle. The clinical and hemodynamic records of six patients with documented acute VSD secondary to myocardial infarction were analyzed to determine which descriptors would be of value in clinically separating these two entities. All six of our patients had a right heart catheterization showing an oxygen step-up consistent with a VSD, and five had a large pulmonary wedge V wave suggesting concomitant mitral insufficiency. The echocardiogram showed only nonspecific chamber enlargement. Since these patients were being considered for open heart surgery to close the VSD, left and right cardiac catheterization including selective coronary arteriography was done. Despite large V waves being present in the pulmonary wedge and/or left atrial pressure tracing in five of the six patients, no mitral insufficiency was present on the left ventricular cineangiograms. It is concluded that a large pulmonary wedge and/or left atrial V wave does not necessarily indicate mitral insufficiency. Since both a VSD and mitral insufficiency are surgically correctable, patients who develop new holosystolic murmurs following myocardial infarction should have complete right and left heart catheterizations with LV angiography for accurate diagnosis if surgical correction of the lesion is contemplated.