Directional coronary atherectomy in acute myocardial infarction.

To date, application of directional coronary atherectomy (DCA) in acute myocardial infarction (AMI) has had limited reports. In eleven patients with AMI, DCA was applied. In three of these patients, DCA was used as a stand-alone procedure without use of thrombolytic agents. In each case a guidewire was placed across the stenosis, and in eight patients balloon angioplasty was utilized as a predilating modality prior to DCA. The thrombolytic agent urokinase was utilized in five of these eight patients, either before, during, or after angioplasty and/or DCA. DCA success (defined as ability to cross the lesion, reduction of less than or equal to 20% in stenosis and thrombolysis--when a thrombus is present) was achieved in 10 of 11 patients. One patient had persistent abrupt reclosure of an LAD lesion, accompanied by hemodynamic compromise, necessitating intra-aortic balloon pump insertion and subsequent emergent coronary artery bypass graft surgery. Final angiograms revealed residual stenoses less than or equal to 20%, and adequate thrombolysis. Significant cardiac events were limited to one emergent CABG, Q wave MI in four patients, and non-Q wave MI in two patients. Clinically all eleven patients improved, survived the AMI/CABG, and were discharged. This clinical experience demonstrates the feasibility and safety of DCA application in selected patients who experience acute myocardial infarction.

Prediction of late cardiac events by dipyridamole thallium imaging in patients undergoing elective vascular surgery.

Dipyridamole thallium scintigraphy has previously been shown to have prognostic value in the preoperative assessment of patients scheduled to undergo vascular surgery, but its effect on the long-term outcome is less well-defined. In the largest series to date, dipyridamole thallium scanning was performed in 360 patients before elective vascular surgery and survivors were followed for a mean of 31 months. In the 327 patients who underwent vascular surgery, operative death and nonfatal myocardial infarction occurred in 4.9 and 6.7%, respectively. A cardiac event (nonfatal myocardial infarction or cardiac death) occurred in 14.4% of patients with a transient thallium defect, as opposed to 1% with a normal scan (p < 0.001). Logistic regression analysis revealed that the best predictor of a perioperative event was the presence of a reversible thallium defect, elevating the risk by 4.3-fold. Late cardiac events occurred in 53 (15.2%) surgical survivors or nonsurgically treated patients. Patients with a fixed perfusion abnormality had a 24% late event rate, compared with 4.9% in those with a normal dipyridamole thallium study (p < 0.01). Cox analysis demonstrated that a fixed thallium defect was the strongest factor for predicting a late event and increased the relative risk by almost fivefold. A history of congestive heart failure was the only significant variable that contributed additional value to that of a fixed defect alone. Life-table analysis confirmed the strong relation of a fixed defect to cardiac event free survival (p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)