Corrected TIMI frame counts correlate with stenosis severity and infarct zone wall motion after thrombolytic therapy

Angiographic and physiologic assessment of coronary flow and myocardial perfusion in the cardiac catheterization laboratory

INTRODUCTION

For many years, coronary angiography has been used to define coronary artery lesions. Angiographic assessment of coronary flow using the TIMI flow grade system (TFG) and the TIMI frame count (TFC) methods have played a significant role in our understanding of coronary artery disease and they have proved useful in prediction of long-term clinical outcomes after myocardial infarction. The availability of invasive techniques to assess the physiological significance of coronary artery lesions allows a more rationale approach to the management of patients, particularly those with intermediate lesions. The TIMI scores and other angiographic parameters such as the TIMI myocardial perfusion grade (TMPG) are now integrated into clinical practice, as are the use of flow wires and pressure recording wires. Other angiographic techniques, (e.g. digital subtraction angiography), which at this time are predominantly research tools, will require software integration into the imaging chain to facilitate real-time analysis.

CONCLUSION

In this article, we provide a comprehensive descriptive review of the different means of assessment of coronary flow in the cardiac catheterization laboratory, focusing on scores deducted from angiography as well as invasive haemodynamic measurements of blood flow and pressure.

Angiographic correlations of patients with small vessel disease diagnosed by adenosine-stress cardiac magnetic resonance imaging

Cardiac magnetic resonance imaging (CMR) with adenosine-stress myocardial perfusion is gaining importance for the detection and quantification of coronary artery disease (CAD). However, there is little knowledge about patients with CMR-detected ischemia, but having no relevant stenosis as seen on coronary angiography (CA). The aims of our study were to characterize these patients by CMR and CA and evaluate correlations and potential reasons for the ischemic findings. 73 patients with an indication for CA were first scanned on a 1.5T whole-body CMR-scanner including adenosine-stress first-pass perfusion. The images were analyzed by two independent investigators for myocardial perfusion which was classified as subendocardial ischemia (n = 22), no perfusion deficit (n = 27, control 1), or more than subendocardial ischemia (n = 24, control 2). All patients underwent CA, and a highly significant correlation between the classification of CMR perfusion deficit and the degree of coronary luminal narrowing was found. For quantification of coronary blood flow, corrected Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) was evaluated for the left anterior descending (LAD), circumflex (LCX) and right coronary artery (RCA). The main result was that corrected TFC in all coronaries was significantly increased in study patients compared to both control 1 and to control 2 patients. Study patients had hypertension or diabetes more often than control 1 patients. In conclusion, patients with CMR detected subendocardial ischemia have prolonged coronary blood flow. In connection with normal resting flow values in CAD, this supports the hypothesis of underlying coronary microvascular impairment. CMR stress perfusion differentiates non-invasively between this entity and relevant CAD.

Myocardial Reperfusion: Its Assessment and Its Relation to Clinical Outcomes

It has become increasingly apparent that epicardial blood flow restoration is necessary, but not sufficient, to achieve optimal clinical outcomes in the setting of acute coronary syndromes. Indeed, clinical outcomes are strongly associated with myocardial perfusion. The diagnostic tools available to assess myocardial perfusion following acute myocardial infarction and their association with clinical outcomes are reviewed here. Many simple angiographic markers--the Thrombolysis in Myocardial Infarction (TIMI) count frame, TIMI myocardial perfusion grade, pulsatile flow--are all readily available measures and are strongly related to clinical outcomes. Other tools, while accurate, remain limited by their high cost, low availability, and complexity for routine use.

Pharmacologic reperfusion therapy for acute myocardial infarction

Acute myocardial infarction (MI) remains a significant problem in terms of morbidity, mortality and healthcare costs. Pharmacologic reperfusion therapies for MI are becoming increasingly complex. This review therefore places contemporary pharmacologic MI developments into perspective. An historical overview of pharmacologic reperfusion therapy for MI is provided, followed by an analysis of current limitations, treatment options, and present and likely future pharmacologic therapies. Adjunctive percutaneous and other treatments are also discussed, to clarify what is becoming a rapidly changing field.