CT angiography has emerged as the diagnostic gold standard for AMI. Early reports demonstrated that an optimal sensitivity and specificity can be achieved utilizing this technique (96% and 94%, respectively).¹¹ Multiple recent reports have confirmed these findings¹² and a recently published meta-analysis showed a pooled sensitivity of 93% and a pooled specificity of 96%,13 suggesting CT angiography may be used as the first-line imaging method.

Duplex ultrasound also was studied for the diagnosis of AMI. Although sensitive in detecting proximal occlusive disease, it was found to be of little aid in detecting occlusive emboli beyond the proximal main vessel or in nonocclusive disease.

Magnetic resonance (MR) angiography has comparable accuracy to CT angiography in diagnosing AMI.¹⁴ The advantage of MR over CT is avoidance of allergy and nephrotoxicity from contrast dye. The major limitations of MR include availability, technical difficulty, and the amount of postacquisition processing of images, which delays the diagnosis.

Conventional angiography is the historical diagnostic gold standard. This modality is now being replaced by CT angiography. The primary advantage of conventional angiography is the ability to simultaneously diagnose and intervene therapeutically. The limitations of conventional angiography are lack of universal availability, the invasive nature of the study, and the potential for complications.

As more nonsurgical treatment options for AMI are being explored (e.g., directed thrombolytics and vasodilators), the role of conventional angiography is becoming increasingly important.¹⁵

Initial treatment of AMI includes active resuscitation, aggressive hydration, and treatment of the underlying etiology. Secondary treatment goals should be to reduce any associated vasospasm, prevent propagation of blood clot, and minimize the potential for reperfusion injury.¹⁵

Fluid repletion is important, as most patients will present with at least moderate dehydration, and the clinical course may be complicated by hypotension from septic shock.⁸

Broad-spectrum antibiotics should be initiated early to target gram-negative and anaerobic bacteria.⁸ Vasopressors can worsen oxygen delivery to the splanchnic circulation and should be minimized, if at all possible.¹⁵ If no contraindication to anticoagulation exists, a heparin infusion should be initiated to minimize thrombus formation and propagation.