Todd A. Dorfman

The effects of medications on myocardial perfusion.

Antianginal and lipid-lowering medications may modify the results of stress myocardial perfusion imaging. Several studies have shown the beneficial potential of these agents in suppressing myocardial ischemia in patients with known coronary artery disease. The effects of nitrates, calcium-channel blockers, beta-blockers, and statins on myocardial perfusion imaging are likely attributable to changes in myocardial blood flow and myocardial oxygen supply-demand ratio. This comprehensive review examines relevant experimental and clinical published data. Technical issues in image interpretation specific to myocardial perfusion imaging and implications of use of cardiac medications to results of myocardial perfusion imaging are discussed.

Takotsubo cardiomyopathy: state-of-the-art review.

Takotsubo cardiomyopathy (TC) is characterized by transient, often severe, left ventricular dysfunction and electrocardiographic changes that might mimic acute myocardial infarction in the absence of significant obstructive coronary artery disease. It is often encountered in elderly women after physical or emotional stress. Excessive catecholamine stimulation, metabolic abnormalities, and microcirculatory dysfunction are thought to be responsible for the manifestations of this disorder. This comprehensive review summarizes relevant published data, atypical presentations, pathophysiology, and management strategy. It also includes a review of 789 patients with TC including nine illustrative cases encountered at our institution.

Role of Myocardial Perfusion Imaging in Patients With End-Stage Renal Disease Undergoing Coronary Angiography

Patients with end-stage renal disease (ESRD) are at high risk of cardiovascular events. This study examined the prognostic power of stress myocardial perfusion imaging (MPI) in 150 patients with ESRD (mean age 53 +/- 9 years; 30% women; 66% with diabetes mellitus) being evaluated for renal transplantation with known coronary anatomy using angiography. Baseline data in addition to perfusion and angiographic parameters were compared between survivors and nonsurvivors. All-cause mortality was defined as the outcome measure. An abnormal MPI result was present in 85% of patients, 30% had left ventricular (LV) ejection fraction (EF) < or =40%, and 40% had multivessel coronary artery disease using angiography. At a mean follow-up of 3.4 +/- 1.5 years, 53 patients died (35%). LVEF < or =40%, LV dilatation (LV end-diastolic volume >90 ml), and diabetes mellitus were associated with higher mortality (all p <0.05). Both total perfusion defect size and mean number of narrowed coronary arteries using angiography were significantly higher in those who died (p <0.05). In a multivariate model, abnormal MPI results (low LVEF or abnormal perfusion) and diabetes alone were independent predictors of death, whereas number of narrowed arteries using coronary angiography was not. Thus, MPI was a strong predictor of all-cause mortality in patients with ESRD. In conclusion, abnormal MPI results independently predicted worse survival and provided more powerful prognostic data than coronary angiography.

Relation Between Heart Rate Response to Adenosine and Mortality in Patients With End-Stage Renal Disease

This study examined the relation between heart rate (HR) response to adenosine and outcome in patients with end-stage renal disease (ESRD). The usual HR increase during adenosine infusion was caused by direct sympathetic stimulation. It was hypothesized that a blunted HR response, which was probably caused by sympathetic denervation, would be associated with a worse outcome in patients with ESRD. One hundred thirty-nine patients with ESRD being evaluated for renal transplantation who underwent coronary angiography and adenosine gated single-photon emission computed tomographic myocardial perfusion imaging were followed up for all-cause mortality. Percentage of change in HR (%DeltaHR) was calculated as [(peak HR during adenosine infusion - HR at rest)/HR at rest] * 100. A control group of 54 patients (normal renal function and no diabetes) was included for comparison of HR responses. Mean age of patients was 54 +/- 9 years, 30% were women, and 68% had type-2 diabetes mellitus. %DeltaHR was 19.2 +/- 18% in patients with ESRD versus 33 +/- 25% in the control group (p <0.0001). At a mean follow-up of 3.4 +/- 1.5 years, 50 patients (36%) with ESRD died. %DeltaHR was lower in nonsurvivors than survivors (12.6 +/- 14% vs 23 +/- 19%; p = 0.0017). Patients with %DeltaHR less than the median value were more likely to have lower left ventricular ejection fraction and larger end-diastolic volume (p <0.05 for each). In a multivariate logistic regression model, %DeltaHR alone was an independent predictor of all-cause mortality (adjusted odds ratio 5.5, 95% confidence interval 2.3 to 12.9, p = 0.0001). In conclusion, patients with ESRD had a blunted HR response to adenosine, and degree of blunting was strongly associated with all-cause mortality.

Regional pericarditis: a review of the pericardial manifestations of acute myocardial infarction.

Regional pericarditis has been described in several settings, but occurs most frequently after transmural myocardial infarction. While the diagnosis remains elusive, it must be considered in all patients with recurrent chest pain following acute myocardial infarction (AMI). Pericarditis classically presents with positional chest pain, a pericardial friction rub, diffuse ST‐segment elevation, and PR depression, but regional ECG changes associated with infarction‐associated pericarditis sometimes exist. Given the magnitude and frequency of AMI, it is imperative to be aware of the myriad of pericardial manifestations of myocardial injury. An illustrative case and a comprehensive review of the literature will be provided. Copyright

Tako-tsubo Cardiomyopathy: A Review of the Literature

The diagnosis of Takotsubo cardiomyopathy (TC) must be considered in all patients who develop transient left ventricular apical (or mid ventricular) ballooning in the absence of obstructive coronary artery disease (CAD). Although the prevalence of TC remains unknown, approximately 2% of all patients presenting with a presumed diagnosis of ST elevation myocardial infarction have been found to have this syndrome. TC usually occurs in the setting of physical or emotional stress associated with excessive sympathetic stimulation and catecholamine release. A literature review and illustrative case report are provided.

The Brain First or the Heart: The Approach to Revascularizing Severe Co‐Existing Carotid and Coronary Artery Disease

Combined symptomatic severe cerebralvascular disease and significant obstructive coronary artery disease frequently exist. 1 , 2 For the past few decades, clinicians have debated the various treatment strategies for these high‐risk patients including staged procedures and hybrid revascularization. While some recommend addressing the more unstable vascular territory first, others prefer to intervene on the carotids prior to performing coronary revascularization. Both surgical and percutaneous options have been explored in various clinical settings, but there are no treatment guidelines to date. Given the frequency and magnitude of this problem, we performed an extensive review of the literature in an attempt to add some much needed clarity. An illustrative case and recommendations are provided. Copyright

Adenosine single photon emission computed tomography for assessing risk after myocardial infarction: recent developments.

Purpose of review While the prognostic power of adenosine single photon emission computed tomography myocardial perfusion imaging has been validated in multiple patient populations including those with known or suspected coronary artery disease, the utility of this modality in assessing risk after an acute myocardial infarction in the primary angioplasty era is still a topic of debate. Recent findings The INSPIRE trial showed that early adenosine single photon emission computed tomography myocardial perfusion imaging is capable of identifying low-risk patients for early hospital discharge after acute myocardial infarction. This novel study demonstrated that intensive medical therapy is a reasonable strategy in low, intermediate, and high-risk post-myocardial infarction patients with preserved left ventricular function. Summary The INSPIRE trial established the role for early adenosine single photon emission computed tomography myocardial perfusion imaging as a tool for risk stratification in stable patients after an acute myocardial infarction and provided evidence that intensive medical therapy is comparable to coronary revascularization in suppressing ischemia and presumably improving cardiac outcomes. It remains to be seen whether these new findings will alter current American College of Cardiology/American Heart Association guidelines, which emphasize a primary role of coronary revascularization in acute coronary syndromes.

Palliative Combined Percutaneous Balloon Aortic Valvuloplasty and Unprotected Left Main Stenting in End Stage Renal Disease

With the aging population and high prevalence of atherosclerosis, an increasing number of patients presenting with heart failure and angina are found to have severe coronary artery disease and severe valvular disease. These patients tend to have multiple co-morbidities such as end stage renal disease and are considered high-risk for surgery. In patients with severe coronary artery disease, severe aortic stenosis, and heart failure with depressed left ventricular systolic function, the options are limited as they are not usually offered surgery, but palliative percutaneous high-risk procedures might be a viable alternative. Though long term results after balloon aortic valvuolpasty are not promising, there is a role for these procedures in high-risk inoperable patients for either palliation or as a bridge to surgery. Unprotected left main percutaneous interventions are also feasible with low complication rates. This review provides mounting evidence that it is reasonable to perform combined palliative balloon aortic valvuolpasty and high-risk coronary artery stenting in certain inoperable patients. An illustrative case is presented that extends the findings of the current literature and demonstrates that combined balloon aortic valvuolpasty and left main stenting could be a safe and effective alternative in the setting of heart failure, left ventricular dysfunction, and end stage renal disease.