Adjunctive pharmacologic agents and mechanical devices in primary percutaneous coronary intervention

Primary percutaneous coronary intervention (PPCI) has been shown to be superior to thrombolysis in patients presenting with ST-segment elevation acute myocardial infarction (STEMI) in reducing death, stroke and re-infarction. However, bleeding and thrombotic complications can occur despite successful PPCI and slow fl ow/no-reflow or poor microvascular reperfusion can occur in a significant minority despite a technically successful procedure. Bleeding or need for peri-procedural transfusion has been shown to increase short- and long-term mortality. Newer anticoagulants appear to reduce the bleeding risk and improve overall clinical outcomes. A novel combination of antiplatelet agents also appears to further improve the outcomes after PPCI. Although PPCI can achieve high rates of epicardial artery patency, some patients experience suboptimal microvascular perfusion, which affects long-term prognosis. Several pharmacologic agents have been shown to improve microvascular perfusion and left ventricular function, although none impacts on clinical outcomes. Of the mechanical devices available to reduce distal embolisation, the simple aspiration catheter holds the most promise in reducing clinical adverse events. Additional research and well designed studies are needed to further enhance the outcomes after PPCI.

Risk stratification for sudden cardiac death after acute myocardial infarction

Many patients who survive an acute myocardial infarction (AMI) remain at risk of recurrent cardiac events and sudden cardiac death after discharge, despite optimal medical treatment. Assessment of the degree of left ventricular dysfunction and residual myocardial ischaemia is useful to identify the patients at greatest risk. In addition, there is increasing evidence that a number of other cardiovascular tests can be used to detect autonomic dysfunction and myocardial substrate abnormalities postAMI that increase the risk of life-threatening ventricular arrhythmias. These investigations include ECG-based tests (signal averaged ECG and T-wave alternans), Holter-based recordings (heart rate variability and heart rate turbulence) and imaging techniques (echocardiography and cardiac magnetic resonance), as well as invasive electrophysiological testing. This article reviews the current evidence for the use of these additional cardiac investigations among survivors of AMI to aid in their risk stratification for malignant ventricular arrhythmias and sudden cardiac death.