Consideration of a new definition of clinically relevant myocardial infarction after coronary revascularization: an expert consensus document from the Society for Cardiovascular Angiography and Interventions (SCAI).

Numerous definitions have been proposed for the diagnosis of myocardial infarction (MI) after coronary revascularization. The universal definition for MI designates post procedural biomarker thresholds for defining percutaneous coronary intervention (PCI)-related MI (type 4a) and coronary artery bypass grafting (CABG)-related MI (type 5) which are of uncertain prognostic importance. In addition, for both MI types cTn is recommended as the biomarker of choice, the prognostic significance of which is less well validated than CK-MB. Widespread adoption of a MI definition not clearly linked to subsequent adverse events such as mortality or heart failure may have serious consequences for the appropriate assessment of devices and therapies, may affect clinical care pathways, and may result in misinterpretation of physician competence. Rather than employing an MI definition sensitive for small degrees of myonecrosis (the occurrence of which, based on contemporary large-scale studies, are unlikely to have important clinical consequences), it is instead recommended that a threshold level of biomarker elevation which has been strongly linked to subsequent adverse events in clinical studies be used to define a "clinically relevant MI." The present document introduces a new definition for "clinically relevant MI" after coronary revascularization (PCI or CABG) which is applicable for use in clinical trials, patient care, and quality outcomes assessment.

Selective adenosine agonists and myocardial perfusion imaging.

Selective adenosine receptor agonists have several advantages for use as stress agents in conjunction with myocardial perfusion imaging compared to the non selective agents such as adenosine and dipyridamole. This review will summarize the pre-clinical and clinical data on the selective adenosine agonist stress agents regadenoson (Lexiscan(®)), binodenoson (CorVue™) and apadenoson (Stedivaze™) that have been studied so far with focus on regadenoson that has the most clinical data published so far. The article will review the adenosine receptor types and properties. It will also review the various attributes of the selective adenosine agonists including their pharmacology, pharmacokinetics and pharmacodynamics, their coronary vasodilatory and hemodynamic effects, their safety and side effects, their interactions with other drugs and their use with myocardial perfusion imaging. The landmark trials of the selective adenosine agonists will be reviewed as well as their use in special patient populations undergoing stress myocardial perfusion imaging.

Hemodynamic evaluation of coronary artery bypass graft lesions using fractional flow reserve.

BACKGROUND: Coronary angiography is limited by its inability to assess the hemodynamic significance of a coronary artery stenosis. The assessment of the physiological significance of saphenous vein graft (SVG) lesions with a pressure wire to determine the fractional flow reserve (FFR) is lacking. METHODS: FFR was determined in 10 SVG lesions of 10 males who had stress myocardial perfusion imaging (MPI) prior to referral for percutaneous coronary intervention for clinical indications. RESULTS: All SVGs had a diameter stenosis (DS) > 50% and 30% had a DS > or = 70%. A significant FFR was present in 30% of patients. Ischemia along the territory of the SVG was present in 20% of patients. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FFR < 0.75 for the detection of ischemia on stress MPI were 50, 75, 33, 85, and 70%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FFR < 0.75 for detecting > or = 70% DS on angiography were 33, 71, 33, 71, and 60%, respectively. There was no significant correlation between FFR and % DS (R(2) = 0.1, P = 0.35). CONCLUSION: The use of FFR to assess the physiological significance of SVG lesions is feasible and provides an acceptable specificity and negative predictive value compared to stress MPI.

Feasibility of primary clot extraction prior to percutaneous coronary intervention in acute myocardial infarction.

OBJECTIVES: To test the feasibility, safety, and in-hospital outcomes of utilizing the FilterWire EZ to extract clot prior to percutaneous coronary intervention (PCI) in patients presenting with acute myocardial infarction (MI). BACKGROUND: PCI in patients with acute MI is associated with a higher incidence of distal embolization, no-reflow, or slow flow partly due to the presence of clot burden. METHODS: The authors describe the feasibility, safety, and outcomes of using a FilterWire EZ distal protection device as a clot extraction device in patients who presented with acute MI and documented clot on coronary angiography. RESULTS: Fifteen consecutive male patients with a mean age of 54 +/- 8 years presented with acute MI (60% ST elevation MI). MI involved left anterior descending artery (n = 4), circumflex artery (n = 3), and right coronary artery (n = 8). Clot extraction followed by PCI reduced the percent diameter stenosis from 94 +/- 12 to 65 +/- 11 (P < 0.001) and restored TIMI 3 flow in all patients without distal embolization. The angiographic, procedural, and clinical success rates were 100%. The mean left ventricular ejection fraction (LVEF) was 52 +/- 8% (range 30-62%) with only three patients (15%) who had an LVEF <50% and five patients (33%) without apparent wall motion abnormalities on echocardiography. CONCLUSIONS: Clot extraction before PCI during acute MI in native coronaries is feasible, safe, and effective in restoring TIMI 3 flow without distal embolization. Whether this approach results in better outcomes and improved LV function compared with standard therapy alone requires further investigation.

Subaortic stenosis missed by invasive hemodynamic assessment.

We present a case of 61-year-old man that was evaluated for possible aortic stenosis but did not show a left ventricular outflow gradient on invasive assessment in the catheterization laboratory. Transthoracic echocardiography showed subaortic stenosis secondary to a discrete membranous structure in the left ventricular outflow tract. This is the first case in the literature of a patient with discrete subaortic stenosis missed by invasive hemodynamic assessment.

Predictors of survival in patients with end-stage renal disease evaluated for kidney transplantation.

Cardiovascular disease is the major cause of mortality in patients with end-stage renal disease (ESRD). This study examined the all-cause mortality in 3,698 patients with ESRD evaluated for kidney transplantation at our institution from 2001 to 2004. Mean age for the cohort was 48+/-12 years, and 42% were women. Stress myocardial perfusion imaging was done in 2,207 patients (60%) and coronary angiography in 260 patients (7%). There were 622 deaths (17%) during a mean follow-up period of 30+/-15 months. The presence and severity of coronary disease on angiography was not predictive of survival. Coronary revascularization did not impact survival (p=0.6) except in patients with 3-vessel disease (p=0.05). The best predictor of death was left ventricular ejection fraction, measured by gated myocardial perfusion imaging, with 2.7% mortality increase for each 1% ejection fraction decrease. In conclusion, left ventricular ejection fraction is a strong predictor of survival in patients with ESRD awaiting renal transplantation. Strategies to improve cardiac function or earlier renal transplantation deserve further studies.

Myocardial perfusion imaging after transient balloon occlusion during percutaneous coronary interventions.

BACKGROUND: Myocardial perfusion imaging (MPI) is highly sensitive in detecting rest ischemia when the radiotracer is injected during the episode of ischemia. The frequency of abnormal MPI results after resolution of ischemia is not well defined. The aim of this study was to determine how long MPI results remain abnormal after transient coronary artery occlusion. METHODS AND RESULTS: Patients undergoing single-vessel percutaneous coronary intervention were injected with technetium 99m sestamibi at 30 to 60 minutes (group 1) (n = 20) or 90 to 120 minutes (group 2) (n = 10) after the last balloon inflation and 24 hours later. There were 30 men aged 59 +/- 8 years. The culprit vessel was the left anterior descending artery in 14 patients and the right coronary artery in 13. The diameter stenosis was reduced from 76.1% +/- 8.7% to 3.0% +/- 6.4% (P < .001). The duration of balloon inflation was 40.3 +/- 12.5 seconds. Chest pain or ST shifts occurred in 66% of patients. A perfusion defect in the territory of the culprit artery was detected in 3 of 20 patients (15%) in group 1 and in 0 of 10 patients (0%) in group 2 (P = .3). One of those three patients had a perfusion defect on MPI done 24 hours later, along with a regional wall motion abnormality on the 2 sets of images. CONCLUSIONS: Abnormal perfusion is seen in a small percentage of patients at 30 to 60 minutes and in none at 90 to 120 minutes after a brief transient balloon occlusion. These results might have important implications in patient care.

Three-vessel coronary artery disease, aortic stenosis, and constrictive pericarditis 27 years after chest radiation therapy: a case report.

A patient with a history of Hodgkin's lymphoma presented with recurrent left pleural effusions and dyspnea on exertion 27 years after radiation therapy. Further evaluation disclosed suspected radiation-induced constrictive pericarditis, aortic stenosis and regurgitation, and severe coronary artery disease. He underwent successful 3-vessel coronary artery bypass grafting, aortic valve replacement, and pericardiectomy.

Palliation of allograft vasculopathy with transluminal angioplasty: a decade of experience.

OBJECTIVES: The goal of this study was to examine the outcomes of percutaneous coronary interventions (PCI) and the predictors for restenosis after cardiac transplantation. BACKGROUND: The role of PCI as definitive therapy for allograft coronary disease (ACD) remains contentious. METHODS: Between January 1, 1990 and December 31, 2000, 62 patients (1.5 to 15.5 years after transplant) underwent 151 procedures resulting in PCIs of 219 lesions. Follow-up after PCI angiography was usually obtained at three and six months, then yearly. Repeat PCI was routinely done to lesions with >60% restenosis. RESULTS: The primary procedural success was 97%. Repeat PCI occurred in 74 of 219 lesions (34%); PCI-related mortality was 2.6% (4 of 151). The freedom from re-PCI (of same vessel site) was 75% at six months, 65% at one year, and 57% at four years. The freedom from restenosis was 95% at one month, 81% at three months, and 57% at six months. Multivariate predictors of freedom from restenosis were the use of stents, higher anti-proliferative immunosuppressant dose, and an era effect. In the setting of one-vessel disease at first PCI, the two-year freedom for ACD death or graft loss was 74%, compared with 75% for two-vessel and 27% for three-vessel disease (p = 0.009). CONCLUSIONS: Despite the increasing effectiveness of PCI for localized ACD, the survival after development of advanced ACD remains poor. Stents appear to increase effectiveness of PCI for ACD, but other factors in the current era contribute to improved outcomes.

Relation between effects of adenosine on brachial artery reactivity and perfusion pattern in patients with known or suspected coronary artery disease.

This study examined the changes in brachial artery diameter and flow velocity in response to intravenous adenosine and compared the results to cuff occlusion and single-photon emission computed tomographic (SPECT) images. The change in diameter was less with adenosine than with cuff occlusion. There was no correlation between the presence of abnormal SPECT images and the responses to adenosine or cuff occlusion in either diameter or flow velocity.

Prevalence of renal artery stenosis in high-risk veterans referred to cardiac catheterization.

OBJECTIVE: The prevalence of atherosclerotic renal artery stenosis (RAS) varies depending on patient selection with no specific guidelines on indications for selective renal angiography in patients referred for coronary angiography. The goal of this study is to determine the prevalence and predictors of renal artery stenosis in hypertensive veterans referred for coronary angiography. DESIGN: Prospective study. SETTING: Tertiary care veterans' administration facility in the USA. PATIENTS, PARTICIPANTS: A total of 90 veterans referred for coronary angiography with an initial ascending aortic pressure > 135 mmHg. INTERVENTIONS: Selective renal angiography was performed following coronary angiography. RESULTS: We found that 28% of the patients had single RAS (> or = 50% stenosis), while 16% had single RAS > or = 70% stenosis, 10% had bilateral RAS >or = 50% and 6% had bilateral RAS > or = 70%. Significant positive univariate predictors of RAS (> or = 50%) were age, peripheral vascular disease (PVD), creatinine level (Cr) and myocardial infarction. Significant multivariate predictors of RAS (> or = 50%) were age > 65 years [relative risk (RR), 3.6; 95% confidence interval (CI), (1.2-10.6)], PVD [RR 3.2, 95% CI (1.1-9.1)] and Cr > 1 mg/dl [RR 4.9, 95% CI (1.53-15.9)]. No complications related to renal angiography were noted. CONCLUSIONS: Selective renal angiography during routine coronary angiography in hypertensive veterans with coronary artery disease is safe and uncovers RAS in many older patients with PVD and renal insufficiency.

Effect of caffeine administered intravenously on intracoronary-administered adenosine-induced coronary hemodynamics in patients with coronary artery disease.

It is believed that caffeine attenuates the coronary hyperemic response to adenosine by blocking the A2a receptors. We studied the effect of caffeine on adenosine-induced myocardial hyperemia measured by fractional flow reserve after intracoronary adenosine administration. Fractional flow reserve was not affected by intravenous caffeine infusion at a dose that was comparable to oral consumption.

Usefulness of preoperative stress perfusion imaging in predicting prognosis after liver transplantation.

The role of preoperative stress single-photon emission computed tomographic (SPECT) imaging in patients with end-stage liver disease who underwent liver transplantation is not well established. We reviewed medical records of patients who had liver transplantation at our institution between January 1998 and November 2001. During this time, 339 patients (213 men, aged 51 +/- 11 years) underwent liver transplantation. Of these, 87 patients had preoperative stress SPECT imaging. Diabetes mellitus (30% vs 11%), hypertension (26% vs 12%), and coronary artery disease (15% vs 7%) were more prevalent in those with than without SPECT (p <0.01 each). The stress SPECT perfusion images were normal in 78 patients (91%) and the left ventricular ejection fraction was 72 +/- 10%. SPECT images revealed ascites in 66% and splenomegaly in 83% of patients. There were 35 total deaths (10%) and 5 nonfatal myocardial infarctions over a mean follow-up of 21 +/- 13 months. Most deaths (32 of 35) were noncardiac and sepsis was the most common cause of death. A normal SPECT study had a 99% negative predictive value for perioperative cardiac events. Kaplan-Meier survival curves showed an 87% 2-year cumulative survival rate in the total group. Thus, in patients undergoing liver transplantation, 2-year survival depends on early noncardiac events. A normal stress SPECT study identified patients at a very low risk for early and late cardiac events despite a higher risk profile. SPECT images also revealed unique findings, such as ascites and splenomegaly, which could produce image artifacts and may interfere with accurate image interpretation.

Prognostic value of myocardial perfusion imaging in predicting outcome after renal transplantation.

Cardiovascular disease is a significant cause of morbidity and mortality after renal transplantation. Pretransplant screening in a subset of these patients for occult coronary artery disease (CAD) may improve outcome. The objective of this study was to examine the outcome of 600 patients after renal transplantation for end-stage renal disease. Prospective outcome data were collected on 600 consecutive patients who had renal transplantation between 1996 and 1998 at our institution at 42 +/- 12 months after surgery. Stress single-photon emission computed tomographic (SPECT) myocardial perfusion imaging was performed in 174 patients before surgery, 136 (78%) of whom had diabetes mellitus. There were a total of 59 events: 17 cardiac deaths, 14 nonfatal myocardial infarctions, and 28 noncardiac deaths. There were 12 cardiac events and 11 noncardiac deaths among those who had SPECT myocardial perfusion imaging. In a multivariate analysis that included important risk factors, age (p = 0.03 and 0.003, respectively) and diabetes (p = 0.02 and 0.005, respectively) were the predictors of total events and cardiac events in patients who did not undergo stress SPECT perfusion imaging. In the subgroup who had stress perfusion imaging, an abnormal perfusion SPECT study was the only predictor of cardiac events (p = 0.006). The 42-month cardiac event-free survival rate was 97% in patients with normal SPECT images and 85% in patients with abnormal SPECT images (RR 5.04, 95% confidence interval 1.4 to 17.6, p = 0.006). Thus, there is a 2.8% event rate per year after renal transplantation, and approximately 50% of these events are noncardiac. In high-risk patients (most of whom had diabetes) with preoperative stress perfusion imaging, those with normal images had significantly lower cardiac events than those with abnormal images. These results have important implications in patient screening and postoperative management.

Treatment of in-stent restenosis in a gastroepiploic artery coronary bypass graft with brachytherapy.

The pedicled right gastroepiploic artery is used as an arterial conduit in a select group of patients undergoing coronary artery bypass grafting with favorable patency and survival rates. Myocardial ischemia can occur, especially secondary to distal anastomotic stenosis. Percutaneous coronary interventions have been successful in treating these stenoses, precluding further challenging and higher risk operations. The restenosis rate of such interventions is unknown. We describe a case of distal right gastroepiploic graft anastomotic stenosis that was initially treated with percutaneous angioplasty, but later required stenting for restenosis. Subsequent in-stent restenosis was successfully treated with angioplasty and brachytherapy via the left axillary approach.

Consideration of a new definition of clinically relevant myocardial infarction after coronary revascularization: an expert consensus document from the Society for Cardiovascular Angiography and Interventions (SCAI).

Numerous definitions have been proposed for the diagnosis of myocardial infarction (MI) after coronary revascularization. The universal definition for MI designates post procedural biomarker thresholds for defining percutaneous coronary intervention (PCI)-related MI (type 4a) and coronary artery bypass grafting (CABG)-related MI (type 5), which are of uncertain prognostic importance. In addition, for both the MI types, cTn is recommended as the biomarker of choice, the prognostic significance of which is less well validated than CK-MB. Widespread adoption of a MI definition not clearly linked to subsequent adverse events such as mortality or heart failure may have serious consequences for the appropriate assessment of devices and therapies, may affect clinical care pathways, and may result in misinterpretation of physician competence. Rather than using an MI definition sensitive for small degrees of myonecrosis (the occurrence of which, based on contemporary large-scale studies, are unlikely to have important clinical consequences), it is instead recommended that a threshold level of biomarker elevation which has been strongly linked to subsequent adverse events in clinical studies be used to define a "clinically relevant MI." The present document introduces a new definition for "clinically relevant MI" after coronary revascularization (PCI or CABG), which is applicable for use in clinical trials, patient care, and quality outcomes assessment.

Oral antiplatelet therapy in diabetes mellitus and the role of prasugrel: an overview.

Diabetics have a prothrombotic state that includes increased platelet reactivity. This contributes to the less favorable clinical outcomes observed in diabetics experiencing acute coronary syndromes as well as stable coronary artery disease. Many diabetics are relatively resistant to or have insufficient response to several antithrombotic agents. In the setting of percutaneous coronary intervention, hyporesponsiveness to clopidogrel is particularly common among diabetics. Several strategies have been examined to further enhance the benefits of oral antiplatelet therapy in diabetics. These include increasing the dose of clopidogrel, triple antiplatelet therapy with cilostazol, and new agents such as prasugrel. The large TRITON TIMI 38 randomized trial compared clopidogrel to prasugrel in the setting of percutaneous coronary intervention for acute coronary syndromes. The diabetic subgroup (n = 3146) experienced considerable incremental benefit with a 4.8% reduction in cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke at 15-month follow-up with prasugrel treatment. Among diabetics on insulin this combined endpoint was reduced by 7.9% at 15 months. Major bleeding was not increased in the diabetic subgroup. This confirms the general hypothesis that more potent oral antiplatelet therapy can partially overcome the prothrombotic milieu and safely improve important clinical outcomes in diabetics.

The scope of coronary heart disease in patients with chronic kidney disease.

Chronic kidney disease (CKD) affects approximately 13% of the U.S. population and is associated with increased risk of cardiovascular complications. Once renal replacement therapy became available, it became apparent that the mode of death of patients with advanced CKD was more likely than not related to cardiovascular compromise. Further observation revealed that such compromise was related to myocardial disease (related to hypertension, stiff vessels, coronary heart disease, or uremic toxins). Early on, the excess of cardiovascular events was attributed to accelerated atherosclerosis, inadequate control of blood pressure, lipids, or inflammatory cytokines, or perhaps poor glycemia control. In more recent times, outcome research has given us further information that relates even lesser degrees of renal compromise to an excess of cardiovascular events in the general population and in those with already present atherosclerotic disease. As renal function deteriorates, certain physiologic changes occur (perhaps due to hemodynamic, inflammatory, or metabolic changes) that decrease oxygen-carrying capacity of the blood by virtue of anemia, make blood vessels stiffer by altering collagen or through medial calcinosis, raise the blood pressure, increase shearing stresses, or alter the constituents of atherosclerotic plaque or the balance of thrombogenesis and thrombolysis. At further levels of renal dysfunction, tangible metabolic perturbations are recognized as requiring specific therapy to reduce complications (such as for anemia and hyperparathyroidism), although outcome research to support some of our current guidelines is sorely lacking. Understanding the process by which renal dysfunction alters the prognosis of cardiac disease might lead to further methods of treatment. This review will outline the relationship of CKD to coronary heart disease with respect to the current understanding of the traditional and nontraditional risk factors, the role of various imaging modalities, and the impact of coronary revascularization on outcome.