Journal of the American College of Cardiology

The Year in Cardiac Imaging

Raymond J. Gibbons, Philip A. Araoz, Thomas C. Gerber — 2012-05-22

This review is a sequel to our 7 previous reports highlighting the most important published research with regard to myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT), cardiac positron emission tomography (PET), cardiac computed tomography (CT), and cardiac magnetic resonance imaging (MRI). This report generally covers the English-language literature between July 1, 2010, and June 30, 2011.

Temporal Trends in and Factors Associated With Bleeding Complications Among Patients Undergoing Percutaneous Coronary Intervention: A Report From the National Cardiovascular Data CathPCI Registry

2012-05-22

Objectives: The purpose of this study was to examine temporal trends in post-percutaneous coronary intervention (PCI) bleeding among patients with elective PCI, unstable angina (UA)/non–ST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI). Background: The impact of bleeding avoidance strategies on post-PCI bleeding rates over time is unknown. Methods: Using the CathPCI Registry, we examined temporal trends in post-PCI bleeding from 2005 to 2009 among patients with elective PCI (n = 599,524), UA/NSTEMI (n = 836,103), and STEMI (n = 267,632). We quantified the linear time trend in bleeding using 3 sequential logistic regression models: 1) clinical factors; 2) clinical + vascular access strategies (femoral vs. radial, use of closure devices); and 3) clinical, vascular strategies + antithrombotic treatments (anticoagulant ± glycoprotein IIb/IIIa inhibitor [GPI]). Changes in the odds ratio for time trend in bleeding were compared using bootstrapping and converted to risk ratio. Results: An approximate 20% reduction in post-PCI bleeding was seen (elective PCI: 1.4% to 1.1%; UA/NSTEMI: 2.3% to 1.8; STEMI: 4.9% to 4.5%). Radial approach remained low (<3%), and closure device use increased marginally from 44% to 49%. Bivalirudin use increased (17% to 30%), whereas any heparin + GPI decreased (41% to 28%). There was a significant 6% to 8% per year reduction in annual bleeding risk in UA/NSTEMI and elective PCI, but not in STEMI. Antithrombotic strategies were associated with roughly half of the reduction in annual bleeding risk: change in risk ratio from 7.5% to 4% for elective PCI, and 5.7% to 2.8% for UA/NSTEMI (both p <0.001). Conclusions: The nearly 20% reduction in post-PCI bleeding over time was largely due to temporal changes in antithrombotic strategies. Further reductions in bleeding complications may be possible as bleeding avoidance strategies evolve, especially in STEMI.

Appropriateness of Coronary Revascularization for Patients Without Acute Coronary Syndromes

2012-05-22

Objectives: The purpose of this study was to determine appropriateness of percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery performed in New York for patients without acute coronary syndrome (ACS) or previous CABG surgery. Background: The American College of Cardiology Foundation (ACCF) and 6 other societies recently published joint appropriateness criteria for coronary revascularization. Methods: Data from patients who underwent CABG surgery and PCI without acute coronary syndrome or previous CABG surgery in New York in 2009 and 2010 were used to assess appropriateness and to examine the variation across hospitals in inappropriateness ratings. Results: Of the 8,168 patients undergoing CABG surgery in New York without ACS/prior CABG who could be rated, 90.0% were appropriate for revascularization, 1.1% were inappropriate, and 8.6% were uncertain. Of the 33,970 PCI patients eligible for rating, 28% lacked sufficient information to be rated. Of the patients who could be rated, 36.1% were appropriate, 14.3% were inappropriate, and 49.6% were uncertain. A total of 91% of the patients undergoing PCI who were classified as inappropriate had 1- or 2-vessel disease without proximal left anterior descending artery disease and had no or minimal anti-ischemic medical therapy. Conclusions: For patients without ACS/prior CABG, only 1% of patients undergoing CABG surgery who could be rated were found to be inappropriate for the procedure according to the ACCF appropriateness criteria, but 14% of the PCI patients who could be rated were found to be inappropriate, and 28% lacked enough noninvasive test information to be rated.

The Need to Improve the Appropriate Use of Coronary Revascularization: Challenges and Opportunities⁎

John Spertus, Paul Chan — 2012-05-22

We stand at the precipice of extraordinary changes in medicine. Prior generations of physicians sought to apply any and all treatments available to preserve the health and functioning of patients, despite incomplete knowledge of disease processes and the evidence base to know the efficacy of alternative treatment strategies. Over the past 4 decades, an explosion of technology and treatments, with varying degrees of clinical evidence to support or refute their value, have been introduced. Congruent with these changes has emerged an unsustainable explosion in the costs of care, such that the economic future of the entire nation seems to be held hostage to “bending the cost curve” and creating a more sustainable model of lowering costs and maximizing the value of healthcare. Professional leadership in defining how best to direct therapy to those who most benefit, while withholding it in those with little to benefit (or are harmed), is the most promising way to maximize the value of healthcare—preserving the benefits of medical progress while limiting costs (). Toward that end, the recently updated Manual of Medical Ethics by the American College of Physicians explicitly states that “physicians have a responsibility to practice effective and efficient health care and to use health care resources responsibly…to help ensure that resources are equitably available” ().

Impact of Coronary Plaque Composition on Cardiac Troponin Elevation After Percutaneous Coronary Intervention in Stable Angina Pectoris: A Computed Tomography Analysis

2012-05-22

Objectives: The authors used multidetector computed tomography (MDCT) to study the relation between culprit plaque characteristics and cardiac troponin T (cTnT) elevation after percutaneous coronary intervention (PCI). Background: Percutaneous coronary intervention is often complicated by post-procedural myocardial necrosis manifested by elevated cardiac biomarkers. Methods: Stable angina patients (n = 107) with normal pre-PCI cTnT levels underwent 64-slice MDCT before PCI to evaluate plaque characteristics of culprit lesions. Patients were divided into 2 groups according to presence (group I, n = 36) or absence (group II, n = 71) of post-PCI cTnT elevation ≥3 times the upper limit of normal (0.010 ng/ml) at 24 h after PCI. Results: Computed tomography attenuation values were significantly lower in group I than in group II (43.0 [26.5 to 75.7] HU vs. 94.0 [65.0 to 109.0] HU, p < 0.001). Remodeling index was significantly greater in group I than in group II (1.20 ± 0.18 vs. 1.04 ± 0.15, p < 0.001). Spotty calcification was observed significantly more frequently in group I than in group II (50% vs. 11%, p < 0.001). Multivariate analysis showed presence of positive remodeling (remodeling index >1.05; odds ratio: 4.54; 95% confidence interval: 1.36 to 15.9; p = 0.014) and spotty calcification (odds ratio: 4.27; 95% confidence interval: 1.30 to 14.8; p = 0.016) were statistically significant independent predictors for cTnT elevation. For prediction of cTnT elevation, the presence of all 3 variables (CT attenuation value <55 HU; remodeling index >1.05, and spotty calcification) showed a high positive predictive value of 94%, and their absence showed a high negative predictive value of 90%. Conclusions: MDCT may be useful in detecting which lesions are at high risk for myocardial necrosis after PCI.

Predicting Periprocedural Myocardial Infarction: Target-Lesion Plaque Characterization With Coronary Computed Tomography Angiography⁎

Jennifer Malpeso, Matthew J. Budoff — 2012-05-22

Periprocedural myocardial infarction (MI) is a well-recognized complication of percutaneous coronary intervention (PCI) occurring in approximately one-third of elective cases (). Mild-to-moderate elevations in cardiac biomarkers after PCI have been shown to be associated with myocardial scar detectable on magnetic resonance imaging () and up to a 35% increase in mortality (); yet whether post-procedural troponin elevation serves as an independent predictor of survival is debatable and has not been definitively established (). Regardless, it seems the ability to identify lesion and vessel characteristics that place patients at risk for future procedural-related major adverse cardiac events would offer interventionalists valuable insight that might be helpful even in routine revascularization procedures. Prior identification of plaques responsible for these events would allow prognostic stratification and prompt initiation of targeted actions to prevent myocardial necrosis, namely through the use of distal embolic protection devices () and upstream loading with high-dose atorvastatin (). Furthermore, as more PCI procedures are being done with same-day discharge, a “high-risk” plaque could be a candidate for overnight stay to evaluate for possibility of post-procedural troponin elevation.

Sudden Cardiac Death in Patients With Human Immunodeficiency Virus Infection

2012-05-22

Objectives: The aim of this study was to determine the incidence and clinical characteristics of sudden cardiac death (SCD) in patients with human immunodeficiency virus (HIV) infection. Background: As the HIV-infected population ages, cardiovascular disease prevalence and mortality are increasing, but the incidence and features of SCD have not yet been described. Methods: The records of 2,860 consecutive patients in a public HIV clinic in San Francisco between April 2000 and August 2009 were examined. Identification of deaths, causes of death, and clinical characteristics were obtained by search of the National Death Index and/or clinic records. SCDs were determined using published retrospective criteria: 1) the International Classification of Diseases-10th Revision, code for all cardiac causes of death; and (2) circumstances of death meeting World Health Organization criteria. Results: Of 230 deaths over a median of 3.7 years of follow-up, 30 (13%) met SCD criteria, 131 (57%) were due to acquired immune deficiency syndrome (AIDS), 25 (11%) were due to other (natural) diseases, and 44 (19%) were due to overdoses, suicides, or unknown causes. SCDs accounted for 86% of all cardiac deaths (30 of 35). The mean SCD rate was 2.6 per 1,000 person-years (95% confidence interval: 1.8 to 3.8), 4.5-fold higher than expected. SCDs occurred in older patients than did AIDS deaths (mean 49.0 vs. 44.9 years, p = 0.02). Compared with AIDS and natural deaths combined, SCDs had a higher prevalence of prior myocardial infarction (17% vs. 1%, p < 0.0005), cardiomyopathy (23% vs. 3%, p < 0.0005), heart failure (30% vs. 9%, p = 0.004), and arrhythmias (20% vs. 3%, p = 0.003). Conclusions: SCDs account for most cardiac and many non-AIDS natural deaths in HIV-infected patients. Further investigation is needed to ascertain underlying mechanisms, which may include inflammation, antiretroviral therapy interruption, and concomitant medications.

Head-to-Head Comparison of Left Ventricular Function Assessment with 64-Row Computed Tomography, Biplane Left Cineventriculography, and Both 2- and 3-Dimensional Transthoracic Echocardiography: Comparison With Magnetic Resonance Imaging as the Reference Standard

2012-05-22

Objectives: This study was designed to compare the accuracy of 64-row contrast computed tomography (CT), invasive cineventriculography (CVG), 2-dimensional echocardiography (2D Echo), and 3-dimensional echocardiography (3D Echo) for left ventricular (LV) function assessment with magnetic resonance imaging (MRI). Background: Cardiac function is an important determinant of therapy and is a major predictor for long-term survival in patients with coronary artery disease. A number of methods are available for assessment of function, but there are limited data on the comparison between these multiple methods in the same patients. Methods: A total of 36 patients prospectively underwent 64-row CT, CVG, 2D Echo, 3D Echo, and MRI (as the reference standard). Global and regional LV wall motion and ejection fraction (EF) were measured. In addition, assessment of interobserver agreement was performed. Results: For the global EF, Bland-Altman analysis showed significantly higher agreement between CT and MRI (p < 0.005, 95% confidence interval: ±14.2%) than for CVG (±20.2%) and 3D Echo (±21.2%). Only CVG (59.5 ± 13.9%, p = 0.03) significantly overestimated EF in comparison with MRI (55.6 ± 16.0%). CT showed significantly better agreement for stroke volume than 2D Echo, 3D Echo, and CVG. In comparison with MRI, CVG—but not CT—significantly overestimated the end-diastolic volume (p < 0.001), whereas 2D Echo and 3D Echo significantly underestimated the EDV (p < 0.05). There was no significant difference in diagnostic accuracy (range: 76% to 88%) for regional LV function assessment between the 4 methods when compared with MRI. Interobserver agreement for EF showed high intraclass correlation for 64-row CT, MRI, 2D Echo, and 3D Echo (intraclass correlation coefficient >0.8), whereas agreement was lower for CVG (intraclass correlation coefficient = 0.58). Conclusions: 64-row CT may be more accurate than CVG, 2D Echo, and 3D Echo in comparison with MRI as the reference standard for assessment of global LV function.

The Exposure-Dependent Effects of Aged Secondhand Smoke on Endothelial Function

2012-05-22

Objectives: The aim of this study was to investigate whether exposure to a range of relatively low concentrations of aged secondhand smoke (SHS), similar to those encountered commonly in the community, would impair endothelial function in a concentration-dependent manner. Background: Exposure to SHS impairs endothelial function in humans. The concentration-dependent relationship for aged SHS effects on endothelial function after an exposure of short duration is unknown. Methods: Thirty-three healthy nonsmokers were exposed to 1 of 2 low levels of aged SHS or to conditioned filtered air for 30 min. The primary end point was change in maximal percent brachial artery flow-mediated dilation after exposure. Results: In a linear regression model for each increase in SHS exposure by 100 μg/m3 respirable suspended particles, the absolute maximal percent brachial artery flow-mediated dilation was reduced by 0.67%. We did not find evidence of a threshold for the effect of SHS on flow-mediated dilation. Conclusions: Short-term exposure to real-world levels of aged SHS for 30 min resulted in a concentration-dependent decrease in endothelial function as measured by flow-mediated dilation.

Perfect Correspondence of Mitral Valve Perforation Using Real-Time 3-Dimensional Transesophageal Echocardiography

2012-05-22

Critical information about the exact anatomic characteristics of the mitral valve can be obtained using real-time 3-dimensional transesophageal echocardiography (RT3D TEE), which could be used in planning an appropriate intervention strategy. The accompanying RT3D TEE images demonstrate the perfect correspondence of mitral valve perforation with gross morphology.

Quadruple Valve Replacement: Visualization With 256-Slice Computed Tomography

Petr Symersky, Ricardo P.J. Budde, Dave R. Koolbergen, Bas A.J.M. de Mol — 2012-05-22

A 51-year-old woman who had undergone aortic, mitral, and tricuspid replacement 9 years previously was admitted for aortic prosthetic obstruction, degeneration of the tricuspid bioprosthesis, and severe pulmonary regurgitation. A pre-operative electrocardiography-gated computed tomography (CT) scan (Philips iCT, Cleveland, Ohio) demonstrated subprosthetic tissue under the aortic prosthesis (A and B, arrows) that was confirmed at surgery (C). Mechanical prostheses were placed in the aortic, tricuspid, and pulmonary positions. After surgery, a residual gradient was found over the aortic valve that was evaluated with a second CT scan. A tilted position of the prosthesis in relation to the left ventricular outflow tract (D and E) was found without obstructive masses and with normal leaflet motion. The other valves functioned normally (F and G, Online Videos 1 and 2). CT imaging helps plan the re-entry strategy for repeat surgery, but also may uncover obstructive valvular masses and abnormal anatomic features as morphological correlates of echocardiographic findings.

A New Adenosine-Independent Index of Stenosis Severity: Why Would One Assess a Coronary Stenosis Differently?

Gérard Finet, Gilles Rioufol — 2012-05-22

We read with interest the paper by Sen et al. () proposing a new adenosine-independent index of stenosis severity. It is suggested that negating the need for adenosine-induced hyperemia () would increase adoption because of the time savings and reduction in side effects. This sounds like a straw man argument. The main reasons not to measure fractional flow reserve (FFR) most often are financial.

Instantaneous Wave-Free Ratio and Fractional Flow Reserve: Close, But Not Close Enough!

Wojciech Rudzinski, Alfonso H. Waller, Edo Kaluski — 2012-05-22

We were greatly interested by the study of Sen et al. (), which proposes the revolutionary, vasodilator-independent index to assess significance of coronary artery stenosis—instantaneous wave-free ratio (iFR). The investigators identified a period during a cardiac cycle when intracoronary resistance is constant and minimal. The pressure ratio across a coronary stenosis during this period was found to correlate well with the fractional flow reserve (FFR) value obtained after adenosine administration. Good overall agreement between iFR and FFR was demonstrated by Bland-Altman analysis. A cutoff value of iFR of 0.83 corresponding to a FFR of 0.8 was calculated based on a receiver-operating characteristic (ROC) analysis.

Instantaneous Wave-Free Ratio or Fractional Flow Reserve Without Hyperemia: Novelty or Nonsense?

2012-05-22

We read the paper by Sen et al. () with great interest. We have a number of concerns regarding the proposed index, instantaneous wave-free ratio (iFR). First, the validity of iFR depends on the assumption that minimum resting myocardial resistance during diastole is equivalent to the mean resistance during maximum hyperemia. We believe that this assumption is not correct. Numerous experimental studies performed over the last 4 decades using true volumetric flow measurement and calculating absolute resistance have provided incontrovertible proof that blood flow at rest in a normal coronary artery is very low during systole (because of the high resistance) and occurs primarily during diastole. During maximum hyperemia, flow increases during both phases of the cardiac cycle, but much more so during diastole. Because blood pressure remains either unchanged or decreases by approximately 10% to 15% (depending on the hyperemic stimulus used), both systolic and diastolic resistance will fall accordingly. Consequently, the minimal diastolic resistance at rest (regardless of whether the entire diastole or the so-called wave-free period is taken) generally is 50% to 100% higher than the average resistance over the complete heart cycle during hyperemia ().

Reply

Sayan Sen, Javier Escaned, Darrel Francis, Justin Davies — 2012-05-22

We sincerely thank these correspondents for their keen interest in our work (). Instantaneous wave-free ratio (iFR) would not have been possible without fractional flow reserve (FFR). The authors are strong supporters and regular users of pressure-derived indices of stenosis severity in their clinical practice, and they acknowledge the great impact that FFR has had on patient management. More than an independent index of stenosis severity, iFR constitutes a scientific attempt to get FFR-like measurements with further simplification of the technique, with the aim of facilitating adoption of physiology in the catheter laboratory and thus improving patient management. We are aware that FFR constitutes the current paradigm of invasive stenosis assessment, and therefore, we welcome the healthy criticisms and the hint of skepticism implicit in the 3 letters sent to the Editor, occasionally with some déjà vu of the initial reactions witnessed during the introduction of FFR.

Correction

2012-05-22

Koskinas K, Chatzizisis YS, Antoniadis AP, Giannoglou GD. Role of Endothelial Shear Stress in Stent Restenosis and Thrombosis: Pathophysiologic Mechanisms and Implications for Clinical Translation. J Am Coll Cardiol 2012;59:1337–49.

Notice

2012-05-22

In the JACC ACC.12 Abstract Supplement (59/13 Suppl A), the ACC inadvertently omitted the name of Michael W. Rich, MD, FACC, in the Acknowledgment section of ACC.12 reviewer names. They apologize for the error.

Retraction Notice

2012-05-22

Syncope in Adults With Pulmonary Arterial Hypertension. J Am Coll Cardiol 59 (2011) 863–7. Rachel J. Le, MD, Eric R. Fenstad, MD, Hilal Maradit-Kremers, MD, Robert B. McCully, MD, Robert P. Frantz, MD, Michael D. McGoon, MD, Garvan C. Kane, MD, PhD.

Inside This Issue

2012-05-22

1849 Raymond J. Gibbons, Philip A. Araoz, Thomas C. Gerber