Incorporating economic analysis in interventional cardiology research.

Evaluative research in interventional cardiology has focused on clinical and technical outcomes. Inclusion of economic data can enhance evaluative research by quantifying the relative economic burden incurred by different therapies. When combined with clinical outcomes, cost data can provide a measure of value (e.g., marginal cost-effectiveness). In some select situations, cost data can also be used as surrogates for complexity of care and morbidity. In this narrative review, we aim to provide a framework for the application of cost data in clinical trials and observational research, detailing how to incorporate this kind of data into interventional cardiology research.

Robust quantitative assessment of collagen fibers with picrosirius red stain and linearly polarized light as demonstrated on atherosclerotic plaque samples.

Collagen is an important component in maintaining structural integrity and functionality of tissues and is modulated in various biological processes. Its visualization and possible quantification using histopathological stains can be important for understanding disease progression or therapeutic response. Visualization of collagen fiber with the histological stain picrosirius red (PSR) is enhanced with polarized light and quantitative analysis is possible using circular polarizers. However, linear polarizers are more commonly available and easier to optically align. The objective of the present study is to demonstrate a novel image acquisition technique and analysis method using linearly polarized light. The proposed imaging technique is based on image acquisition at multiple slide rotation angles, which are co-registered to form a composite image used for quantitative analysis by pixel intensity or pixel counting. The technique was demonstrated on multiple human coronary samples with varying histopathologies and developed specifically to analyze cap collagen in atherosclerotic plaque. Pixel counting image analysis was found to be reproducible across serial tissue sections and across different users and sufficiently sensitive to detect differences in cap structural integrity that are likely relevant to prediction of rupture risk. The benefit of slide rotation angle under linear polarization to acquire images represents a feasible and practical implementation for expanding the general utility of PSR for quantitative analysis.

Five-year follow-up of patients treated for coronary artery disease in the face of an increasing burden of co-morbidity and disease complexity (from the NHLBI Dynamic Registry).

Management of coronary artery disease (CAD) has evolved over the past decade, but there are few prospective studies evaluating long-term outcomes in a real-world setting of evolving technical approaches and secondary prevention. The aim of this study was to determine how the mortality and morbidity of CAD has changed in patients who have undergone percutaneous coronary intervention (PCI), in the setting of co-morbidities and evolving management. The National Heart, Lung, and Blood Institute Dynamic Registry was a cohort study of patients undergoing PCI at various time points. Cohorts were enrolled in 1999 (cohort 2, n = 2,105), 2004 (cohort 4, n = 2,112), and 2006 (cohort 5, n = 2,176), and each was followed out to 5 years. Primary outcomes were death, myocardial infarction (MI), coronary artery bypass grafting, repeat PCI, and repeat revascularization. Secondary outcomes were PCI for new obstructive lesions at 5 years, 5-year rates of death and MI stratified by the severity of coronary artery and co-morbid disease. Over time, patients were more likely to have multiple co-morbidities and more severe CAD. Despite greater disease severity, there was no significant difference in death (16.5% vs 17.6%, adjusted hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.74 to 1.08), MI (11.0% vs 10.6%, adjusted HR 0.87, 95% CI 0.70 to 1.08), or repeat PCI (20.4% vs 22.2%, adjusted HR 0.98, 95% CI 0.85 to 1.17) at 5-year follow-up, but there was a significant decrease in coronary artery bypass grafting (9.1% vs 4.3%, adjusted HR 0.44, 95% CI 0.32 to 0.59). Patients with 5 co-morbidities had a 40% to 60% death rate at 5 years. There was a modestly high rate of repeat PCI for new lesions, indicating a potential failure of secondary prevention for this population in the face of increasing co-morbidity. Overall 5-year rates of death, MI, repeat PCI, and repeat PCI for new lesions did not change significantly in the context of increased co-morbidities and complex disease.

Comparison of invasive and noninvasive assessment of aortic stenosis severity in the elderly.

BACKGROUND: Aortic valve area (AVA) in aortic stenosis (AS) can be assessed noninvasively or invasively, typically with similar results. These techniques have not been validated in elderly patients, where common assumptions make them most prone to error. Accurate assessment of AVA is crucial to determine which patients are appropriate candidates for aortic valve replacement. METHODS AND RESULTS: Fifty elderly patients (mean 86 years, 46% female) referred for cardiac catheterization to evaluate AS also underwent transthoracic echocardiography within 24 hours. To minimize assumptions all patients had 3-dimensional echocardiography (Echo-3D), and at catheterization using directly measured oxygen consumption (Cath-mVo(2)) and thermodilution cardiac output (Cath-TD). Correlation between Cath-mVo(2) and Echo-3D AVA was poor (r=0.41). Cath-TD AVA had a moderate correlation with Echo-3D AVA (r=0.59). Cath-mVo(2) (AVA=0.69 cm(2)) and Cath-TD (AVA=0.66 cm(2)) underestimated AVA compared with Echo-3D (AVA=0.76 cm(2;) P=0.08 for comparison with Cath-mVo(2); P=0.001 for Cath-TD). Compared with Echo-3D, the sensitivity and specificity for determining critical disease (AVA <0.8 cm(2)) were 81% and 42% for Cath-mVo(2), and 97% and 53% for Cath-TD. The only independent predictor of the difference between noninvasive and invasive AVA was stroke volume index (P<0.01). Resistance, a less flow-dependent measure, showed a stronger correlation between Echo-3D and Cath-mVo(2) (r=0.69), and Echo-3D and Cath-TD (r=0.77). CONCLUSIONS: Standard techniques of AVA assessment for AS show poor correlation in elderly patients, with frequent misclassification of critical AS. Less flow-dependent measures, such as resistance, should be considered to ensure that only appropriate patients are treated with aortic valve replacement.

Patient satisfaction is comparable to early discharge versus overnight observation after elective percutaneous coronary intervention.

BACKGROUND: Previous investigation has suggested that early discharge after percutaneous coronary intervention (PCI) is feasible and safe, but these studies have utilized largely radial approaches or been conducted in non-U.S. cohorts. We sought to assess patient satisfaction, safety and cost of a strategy of selective early discharge in U.S. patients undergoing PCI via a femoral approach with contemporary adjunctive pharmacologic and hemostasis agents. METHODS AND RESULTS: Patients with stable coronary artery disease undergoing elective PCI were prospectively recruited and randomized to either routine care, with an overnight hospital stay, versus early discharge 2 hours following successful PCI with adjunctive bivalirudin therapy and a femoral arterial closure device at the end of the procedure. The primary endpoints were safety and patient satisfaction as measured by a validated patient satisfaction survey during the index hospital stay and at 30 days. A total of 39 patients were randomized, with 20 to routine care and 19 to early discharge. There was no difference in major safety endpoints including death, non-fatal MI, urgent target lesion revascularization and thrombolysis in myocardial infarction (TIMI) major bleeding, with none in either group. Mean patient satisfaction scores were similar and high in both groups (89.6 for early discharge patients and 90.7 for routine care patients, p = 0.68). There was lower cost in the early discharge group, with a mean cost of 8,604 USD versus 10,565 USD in the routine care group (mean difference 1,961 USD, 95% confidence interval, -96 USD to 4,017 USD). CONCLUSION: Patients undergoing elective PCI for stable coronary artery disease may have similar safety and satisfaction with early discharge when using a careful strategy that incorporates optimal stent and hemostasis results and contemporary adjunctive anticoagulation therapy, with lower cost. This strategy may serve as a basis for a larger-scale randomized trial.

Porcine models of coronary atherosclerosis and vulnerable plaque for imaging and interventional research.

Animal models facilitate our understanding of human disease by providing a controlled environment permitting testing of mechanisms of disease, diagnostic technologies and therapeutic interventions. The ideal animal model should display coronary lesions resembling those seen in human atherosclerosis. No suitable large animal model of high-risk (vulnerable) plaque exists. Lack of such a model has hampered studies designed to validate imaging technologies and to scrutinise the effects of therapeutic interventions in atherosclerotic arteries. Several porcine models of advanced human-like coronary atherosclerosis exist. In this review some of the most promising porcine models are discussed, focusing on their applicability in the development and validation of coronary imaging technologies and interventional devices. In the evolving era of technological development, the availability and use of such animal models of advanced human-like coronary atherosclerosis and vulnerable plaque will become critically important in the preclinical testing of emerging technologies in interventional cardiology.