Sanjeev Puri

Abnormal Coronary Flow Velocity Reserve After Coronary Artery Stenting in Patients Role of Relative Coronary Reserve to Assess Potential Mechanisms

BACKGROUND Absolute coronary flow velocity reserve (CVR) after stenting may remain abnormal as a result of several different mechanisms. Relative CVR (rCVR=CVR(target)/CVR(reference)) theoretically normalizes for global microcirculatory disturbances and facilitates interpretation of abnormal CVR. METHODS AND RESULTS To characterize potential mechanisms of poststent physiology, CVR was measured using a Doppler-tipped angioplasty guidewire in 55 patients before and after angioplasty, after stenting, and in an angiographically normal reference vessel. For the group, the percent diameter stenosis decreased from 75+/-13% to 40+/-18% after angioplasty and to 10+/-9% (all P<0.05) after stent placement. After angioplasty, CVR increased from 1.63+/-0.71 to 1.89+/-0.55 (P<0.05) and after stent placement, to 2.48+/-0.75 (P<0.05 versus pre- and postangioplasty). After angioplasty, rCVR increased from 0.64+/-0.26 to 0.75+/-0.23 and after stent placement to 1.00+/-0.34. In 17 patients with CVR(stent) < or = 2.0, increased basal coronary flow, rather than attenuated hyperemia, was responsible in large part for the lower CVR(stent) compared with patients having CVR(stent) >2.0. In 8 patients with CVR(stent) <2.0, a normal rCVR supported global microvascular disease. The subgroup of 9 patients with CVR(stent) <2.0 and abnormal rCVR (16% of the studied patients) may require a pressure-derived fractional flow reserve to differentiate persistent obstruction from diffuse atherosclerotic disease or microvascular stunning. CONCLUSIONS Although a majority of patients after stenting normalize CVR for the individual circulation (ie, normal CVR or normal rCVR), in those with impaired CVR(stent), the analysis of coronary flow dynamics suggests several different physiological mechanisms. Additional assessment may be required to fully characterize the physiological result for such patients to exclude remediable luminal abnormalities.

Hemodynamic rounds series II: Coronary hemodynamics for angioplasty and stenting after myocardial infarction: use of absolute, relative coronary velocity and fractional flow reserve.

The application of absolute coronary velocity reserve, relative coronary velocity reserve, and pressure-derived fractional flow reserve of the myocardium may have influence on decision making for angioplasty and stenting in patients after myocardial infarction. This case highlights the use and limitations of these techniques in the setting of myocardial infarction where absolute coronary flow reserve may be commonly compromised. The role for absolute, relative coronary, and fractional flow reserve are discussed.

In vivo and in vitro studies on the mechanism and clinical significance of spontaneous echocardiographic contrast in patients with atrial dysrhythmias

The pathogenesis of spontaneous echocardiographic contrast (SEC) is complex and multifactorial. Although originally described in low-flow state situations such as in the left atrium of patients with mitral stenosis or in the false lumen of patients with aortic dissection, its detection is highly dependent on technical factors such as the frequency of the transducer used. Multiple blood components have been implicated in SEC formation and erythrocyte aggregation currently appears to be the most likely mechanism. SEC is related to atrial fibrillation and is commonly found in patients with thrombus or prior history of thromboembolism. In addition, it may represent a prognostic marker for patients with atrial fibrillation because patients with SEC have a higher incidence of subsequent thromboembolic events. Therapeutic options include anticoagulation and, perhaps, antiplatelet therapy. Further prospective studies are necessary to better define SEC pathogenesis and treatment.

Stenting for spontaneous left internal mammary artery dissection: A case report

We present a case of a spontaneously occurring mid LIMA dissection found on routine cardiac catheterization. We report our evaluation and intervention for this exceedingly rare phenomenon. Catheter Cardiovasc Interv 2003;60:389–391.

THE ECONOMIC IMPACT OF IMPLEMENTATION OF APPROPRIATE USE CRITERIA ON VOLUME OF PCI CASES AND MEDICAL COST SAVINGS AT A LARGE COMMUNITY HOSPITAL

Nationally, more than

Risk Stratification: Exercise Testing, Imaging, and Cardiac Catheterization

10 billion is spent annually on Percutaneous Coronary Interventions (PCI). The ACC developed an Appropriate Use Criteria (AUC) for coronary revascularization in an attempt to curb rising healthcare costs and to assist both clinicians and patients in choosing the best procedure

Effect of intravenous contrast for left ventricular opacification and border definition on sensitivity and specificity of dobutamine stress echocardiography compared with coronary angiography in technically difficult patients.

Each year, approximately 1.5 million patients in the United States suffer an acute myocardial infarction (AMI) and 500,000 patients die (1). Reperfusion therapy, increased use of adjunctive medication such as aspirin, β-blockers, angiotensin-converting enzyme (ACE) inhibitors, and hypocholesterolemic treatment coupled with better risk stratification to identify those most likely to benefit from early coronary revascularization has led to significant improved long-term prognosis after myocardial infarction (MI).