Dr. Bashore opened by noting that the relevant guidelines are available at the web site of the American College of Cardiology (www.acc.org).

His first topic was the use of primary percutaneous intervention as an alternative to thrombolytic therapy. The major indicators include timing within 12 hours of symptom onset, persistent pain, cardiogenic shock, or contraindication to thrombolytics.

Rescue interventions are generally done when there is less than TIMI 2 flow rate in the infarct-related artery or there is evidence of persistent ischemia or hemodynamic instability. He noted that current guidelines do not recommend routine catheterization within the first 48 hours after thrombolytic therapy.

Dr. Bashore stated that much discussion about the prognostic value of angiography is based on interpretation of findings. Perfusion can be assessed by TIMI flow rates or frame counts. Counts represent an attempt to standardize results into a simple index. The frame count marks the time required for contrast to reach a preselected landmark; it appears to have more prognostic power than flow rate.

Another way in which prognostic information can be obtained involves TIMI myoperfusion grades, which range from Grade 0 (no or minimal blush) to Grade 3 (normal blush with persistent contrast to end of washout). Intermediate grades reflect microvascular delay in contrast washout.

High-risk patients should generally have catheterization as part of risk stratification. He noted the following: patients older than 75 years, those in Killip class II-IV, patients with a non-ST-elevation infarction or with new left bundle branch block, those with diabetes, and those with cTroponin I levels greater than 1.5 ng/mL or with a high BNP level.

Dr. Bashore noted that the risk stratification guidelines encourage physician flexibility. He drew attention to findings that indicate certain populations, including women and elderly patients, are catheterized less frequently than expected and reminded physicians to be aware of those patients.

He concluded by noting that there is a clear trend toward an invasive strategy emphasizing catheterization based on mortality-rate findings from a number of studies published recently, especially in 2000 and 2001.