Peter B. Berger

Clinical safety of magnetic resonanceimaging early after coronary artery stent placement

OBJECTIVESnOur aim was to examine the rate of adverse cardiac events in patients undergoing magnetic resonance imaging (MRI) <8 weeks after coronary stent placement.nnnBACKGROUNDnThe risk of coronary stent thrombosis from dislodgement due to MRI early after stent placement is not well defined. Manufacturers recommend postponing MRI studies until eight weeks after coronary stent placement.nnnMETHODSnWe analyzed the Mayo Clinic Rochester Percutaneous Coronary Intervention Database and examined records of 111 patients who underwent MRI <8 weeks after coronary stent placement treated with aspirin and a thienopyridine. Occurrence of death, myocardial infarction (MI), and repeat revascularization within 30 days of MRI were recorded.nnnRESULTSnMagnetic resonance imaging (1.5 tesla) was performed within a median of 18 days (range, 0 to 54 days) after coronary stent placement. Four noncardiac deaths occurred, and three patients had repeat revascularization procedures. Stent thrombosis did not occur (95% confidence interval, 0% to 3.3%).nnnCONCLUSIONSnMagnetic resonance imaging <8 weeks after coronary stent placement appears to be safe, and the risk of cardiac death or MI due to stent thrombosis is low. Postponing MRI does not appear to be necessary.

An immediate invasive strategy for the treatment of acute myocardial infarction early after noncardiac surgery

M from myocardial infarction (MI) early after noncardiac surgery ranges from 40% to 70%.1 The high mortality is multifactorial, in part from significant comorbidity. One contributor to the high mortality is the inability to administer thrombolytic therapy because of the risk of bleeding at the surgical site.2 Direct angioplasty also reduces mortality from MI and compares favorably with thrombolytic therapy.3 Because of the lower risk of bleeding associated with angioplasty, this procedure may be beneficial in the treatment of early postoperative MI; however, to our knowledge, there are no studies of direct angioplasty in such patients. Therefore, we studied the clinical course and outcome of patients at our institution undergoing immediate angiography for acute MI early after noncardiac surgery. • • • We analyzed the catheterization laboratory and surgical databases at Mayo Clinic between 1990 and 1998 and identified 48 consecutive patients referred for coronary angiography for acute MI within 7 days after noncardiac surgery. All patients had ischemictype chest pain for

Evaluation of long-term survival after successful percutaneous coronary intervention among patients with chronic renal failure ∗

30 minutes or hemodynamic instability with ischemic electrocardiographic changes. Cardiogenic shock was defined as systolic blood pressure ,90 mm Hg for .1 hour unresponsive to fluid. Successful angioplasty was defined as a reduction in stenosis of

Cardiogenic Shock Complicating ST-Segment Elevation Acute Coronary Syndrome

20% and a residual stenosis ,50% by visual estimation. The baseline clinical characteristics of the study population, preoperative tests performed, and medications at the time of admission are listed in Table 1. Types of surgical procedures included the following: intraabdominal, 14 patients; orthopedic, 11; vascular, 11; urologic, 5; neurologic, 3; and other types, 4. Intraoperative instability was present in 5 patients. Thirty-three patients had ST-segment elevation (anterior in 14), 8 had ST-segment depression, 4 had a new bundle branch block, and 3 had other changes. The median duration between surgery and symptom onset was 1 day (mean 1.6 6 1.9), and from symptom onset to coronary angiography, 4 hours (mean 11.1 6 17.4). Shock was present in 21 patients, and cardiac arrest occurred in 12 before angiography. Angiography revealed 1-vessel disease in 6 and multivessel disease in 42. The infarct artery was the left anterior descending in 18 patients, right coronary in 15, circumflex in 7, left main in 1, and a vein graft in 2. The infarct artery could not be determined in 5 patients; 1 had anterior ST elevation and 70% stenosis in all 3 coronary arteries but no occlusion or thrombus on angiography. The other 4 each had what appeared to be several chronically occluded vessels. The infarct artery was partially or totally occluded in 32 patients; there was evidence of thrombus in 30. Of 41 patients who underwent angioplasty (Figure 1), the procedure was successful in 30, 6 of whom had stent placement. Three patients underwent bypass surgery: of those, 2 had surgery immediately after angiography, 1 of whom developed severe papillary muscle dysfunction and also underwent mitral valve From the Division of Cardiovascular Diseases and Internal Medicine, the Department of Anesthesiology, and the Department of Surgery, Mayo Clinic and Mayo Foundation, Rochester, Minnesota. Dr. Berger’s address is: Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905. E-mail: berger.peter@mayo.edu. Manuscript received October 12, 2000; revised manuscript received and accepted November 21, 2000. TABLE 1 Baseline Characteristics (n 5 48)

Impact of coronary artery stents on mortality and nonfatal myocardial infarction: meta-analysis of randomized trials comparing a strategy of routine stenting with that of balloon angioplasty

We studied the long-term outcomes after percutaneous coronary intervention in dialysis patients and in patients with chronic renal failure (CRF) (serum creatinine > or = 3.0 mg/dl). All-cause mortality at 1 year was 2.9% for the control group, 16.2% for the group with CRF, and 14.1% for dialysis patients. Cardiac mortality at 1 year was 1.9% for ther control group, 15.2% for the group with CRF, and 10.0% for dialysis patients.

Predictors of improvement in left ventricular function after percutaneous revascularization of occluded coronary arteries: A report from the Total Occlusion Study of Canada (TOSCA)

Severe left ventricular dysfunction sufficient to cause cardiogenic shock can result from each of the acute coronary syndromes, including ST-elevation myocardial infarction, non—ST-elevation myocardial infarction, and unstable angina without infarction (1). This chapter will focus on shock resulting from ST-elevation myocardial infarction. In part, because the definition of cardiogenic shock and the study population with acute coronary syndromes have varied in different series, the reported incidence of cardiogenic shock complicating acute coronary syndromes has also varied. In two large, international series of patients receiving thrombolytic therapy for acute myocardial infarction, the reported incidence of shock differed between countries, being greatest in the United States; whether this was the result of differing adherence of the diagnosis, different vigilance for identifying diagnostic criteria, the result of different therapies used in the countries, or true geographic variability, is unknown (2,3).