Implementing a 'Lead [Apron]-Free' Cardiac Catheterization: Current Status.

PURPOSE OF REVIEW: In this review, we discuss the status of novel radiation shielding and other methods to reduce radiation exposure and its associated health risks within the CCL. RECENT FINDINGS: There are many devices on the market each with its unique advantages and inherent flaws. Several are available for widespread use with promising data, while others still in development. The field of percutaneous transcatheter interventions includes complex procedures often involving significant radiation exposure. Increased radiation exposes the proceduralist and CCL staff to potential harm from both direct effects of radiation but also from the ergonomic consequences of daily use of heavy personal protective equipment. Here we discuss several innovative efforts to reduce both radiation exposure and orthopedic injury within the CCL that are available, leading to a safer daily routine in a "lead [apron]-free" environment.

Evidence-Based Practices in the Cardiac Catheterization Laboratory: A Scientific Statement From the American Heart Association.

Cardiac catheterization procedures have rapidly evolved and expanded in scope and techniques over the past few decades. However, although some practices have emerged based on evidence, many traditions have persisted based on beliefs and theoretical concerns. The aim of this review is to highlight common preprocedure, intraprocedure, and postprocedure catheterization laboratory practices where evidence has accumulated over the past few decades to support or discount traditionally held practices.

When Intracoronary Anatomy is Superior to Physiology.

Physiologic assessment has become an essential tool to guide revascularization decisions due to the multiple limitations of angiographic and anatomic measures of physiologic significance. However, in certain cases the apparent physiologic measurement may not accurately reflect the severity of coronary disease compared with anatomical measurements. This article will review how anatomy trumps physiology in cases of acute coronary syndromes, left main disease, saphenous vein graft lesions, and myocardial bridging, and how to overcome the limitations of physiologic measurement in these clinical situations.

Physiologic Lesion Assessment to Optimize Multivessel Disease.

PURPOSE OF REVIEW: Multivessel coronary artery disease, defined as significant stenosis in two or more major coronary arteries, is associated with high morbidity and mortality. The diagnosis and treatment of multivessel disease have evolved in the PCI era from solely a visual estimation of ischemic risk to a functional evaluation during angiography. This review summarizes the evidence and discusses the commonly used methods of multivessel coronary artery stenosis physiologic assessment. RECENT FINDINGS: While FFR remains the gold standard in coronary physiologic assessment, several pressure-wire-based non-hyperemic indices of functional stenosis have been developed and validated as well as wire-free angiographically derived quantitative flow ratio. Identifying and treating functionally significant coronary atherosclerotic lesions reduce symptoms and major adverse cardiovascular events. Coronary physiologic assessment in multivessel disease minimizes the observer bias in visual estimates of stenosis, changes clinical management, and improves patient outcomes.

Is stealing still a crime? Comment on left internal mammary artery side branch intervention in the management of coronary steal syndrome following coronary artery bypass grafting.

Post-coronary artery bypass graft surgery (CABG) angina has been attributed unligated thoracic side branches competing with LIMA-LAD flow. Case reports suggest thoracic branch occlusion can relieve angina. Phasic arterial blood flow and direct measurements argue against the existence of LIMA steal.

How strong is the warranty of a negative FFR? Comment on long-term outcome after deferred revascularization due to negative fractional flow reserve in intermediate coronary lesions by Weerts et al.

Outcomes of deferred PCI based on negative FFR are generally good. This study demonstrated deferred target lesion failure with FFR >0.80 in 7% and related it to coexistent risk factors, such as multivessel disease, diabetes, and SVG lesions. A negative FFR is only one variable on the continuum of ischemic risk, but in general provides an excellent prognostic tool.

Do hemodynamics matter in the treatment of patients with submassive pulmonary emboli?

The present article examines the right heart (RH) pressures of patients with submassive pulmonary embolism before and after catheter-directed thrombolysis (CDT). 40% of patients had a low cardiac output (CI ≤1.8 L/min/m2 ) despite normally preserved blood pressure. After thrombolysis, CI increased and pulmonary artery pressures decreased. Although routine RH pressure measurements may help in CDT management and possibly serve as a surrogate outcome measure, more comprehensive pulmonary embolism trials are needed to solidify the role of hemodynamics in this setting.

Hemodynamics of constrictive pericarditis and restrictive cardiomyopathy.

Constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM) are indolent disabling diseases of diastolic function. The two conditions share common pathophysiologic features, resulting in similar and overlapping clinical presentations, echocardiographic findings, and hemodynamic characteristics. However, their clinical course differs, as CP is surgically curable whereas RCM is a chronic condition managed medically. Separating these two entities is based on delineation of anatomic and physiologic derangements employing multimodality hemodynamic interrogation by advanced imaging techniques (Echo-Doppler, CT, and especially MRI) combined with sophisticated invasive hemodynamics.

Collaterals in STEMI patients: An uncommon but critical lifeline.

Angiographically visible collaterals are seen in a minority of STEMI patients, predominantly to the RCA and in patients with delays to reperfusion. Patients with visible collaterals were less likely to have cardiogenic shock and tended to have a longer survival. Further studies will determine the mechanisms of collateral formation and their protective associations.

Predicting post stent fractional flow reserve virtually from quantitative flow ratio - Can we really get there from here?

This study compared virtual (residual) post-PCI QFR and actual post-PCI QFR from pre- and post-stent angiograms in predicting post-PCI FFR. While there was no difference in mean values, compared with post-PCI FFR, the post-PCI QFR correlated better than residual QFR. As the CFD algorithms improve, post-PCI QFR can potentially serve as a quality control after PCI to reduce post-PCI angina and adverse outcomes.

Effects of intraaortic balloon counterpulsation on translesional coronary hemodynamics.

The intraaortic balloon pump (IABP) provides counterpulsation by displacing a 40-50 cc blood volume during diastole augmenting diastolic pressure. The rapid deflation of the balloon timed to the initiation of systole reduces the afterload of ventricular ejection and thus peak systolic pressure. As a direct result, IABP increases mean arterial pressure (MAP) and peak diastolic pressure while reducing systolic pressure and myocardial work. IABP increases coronary flow velocity in non-obstructed vessels, but does not increase flow across a severe obstruction as shown by intracoronary Doppler flow studies (Kern et al., Circulation, 1993;87:500-511 and Kern et al., Circulation 1991;84:II-485). There are few studies using pressure sensor guidewires to confirm these responses. We present a case illustrating the translesional hemodynamics using an angioplasty sensor pressure wire across a severe stenosis and the unique influence of the IABP.

Effects of pericardial tamponade on the hemodynamics of aortic stenosis.

Compressive pericardial physiology (i.e., cardiac tamponade) reduces ventricular chamber volume/filling and cardiac output, which exacerbates coexisting hemodynamic derangements. In this hemodynamic rounds, we demonstrate the interaction of two hemodynamic conditions in one patient with acute pericardial tamponade in the setting of aortic stenosis (AS). Simultaneous pressures across the aortic valve before and after relief of cardiac tamponade demonstrate an acute and uncommon improvement in the hemodynamics of AS.

Vive la difference: Factors and mechanisms predicting discrepancy between iFR and FFR.

FFR/iFR is discordant in 15-20% of cases, at times causing confusion about revascularization decisions. The CONTRAST substudy identifies lesion location, lesion severity, and bradycardia as major predictors for FFR/iFR discordance, with age a minor predictor. Each of these predictors can be explained physiologically through the mechanisms related to resting and hyperemic pressure loss across different patterns of atherosclerotic stenoses. A logical approach to using both resting and hyperemic pressure ratios is proposed.

What patients want.

Patients may have preferences and priorities for their catheterization procedure that may differ from the operator's expectations. This online survey of normal volunteers suggested that patients place the highest value on same-day discharge and lesser values for radiation exposure, bleeding risk, and access site. Patient-centered care needs to increasingly emphasize same-day discharge after PCI for highest patient satisfaction.

Fractional flow reserve from intravascular ultrasound imaging: Computational fluid dynamics to the rescue?

IVUS measurements of luminal area have only modest correlations to FFR. This study used IVUS 3D anatomical data in a computational fluid dynamic model to estimate FFR with a reasonable degree of accuracy. Further studies are needed to refine the models to make them more accurate and practical for routine use.

Every TAVR deserves a cardiac implantable electronic device specialist.

TAVR patients given pacemakers operating in mandatory DDD mode had more ventricular pacing, heart failure hospitalization, and mortality compared with AAI-DDD or VVI modes. AV conduction disturbances are often transient after TAVR. Minimizing ventricular pacing where possible avoids the risk of pacemaker-induced cardiomyopathy. Pacemaker specialists should be consulted for any TAVR patient with mild rhythm abnormalities given the high incidence of AV block.

The calculus of preloading antiplatelet agents in ST-elevation myocardial infarction: Does it make a difference?

There is limited evidence supporting the preloading of potent oral P2Y12 inhibitors in ST-elevation myocardial infarction (STEMI). This study demonstrates that longer pretreatment times were associated with improved angiographic coronary flow grades and ST-segment resolution. Although larger studies would be needed to prove a clinical benefit, in the absence of harm preloading in STEMI would be the most reasonable strategy.

Evaluation of the severity of mitral stenosis in patient with pulmonary hypertension: Role of exercise hemodynamics.

Dyspnea due to mitral stenosis (MS) and/or pulmonary hypertension (PHT) in patients who may have both conditions presents a challenging diagnostic dilemma. The hemodynamic response to exercise is probably the most helpful method to arrive at the correct diagnosis and treatment algorithm. In this hemodynamic rounds discussion, we evaluated a patient with MS and PHT prior to the decision for mitral valvuloplasty. KEY POINTS: Symptoms in patients with mitral stenosis and pulmonary hypertension cannot always be attributed to one pathology. Catheter-based hemodynamics are often needed to differentiate valve from lung disease. Exercise hemodynamics can clarify the predominant pathology in complex clinical scenarios.

Bifurcation lesion assessment with advanced quantitative coronary angiography: A method still wanting.

Bifurcations are particularly prone to errors in visual estimation of diameter stenosis. Dedicated bifurcation QCA software confirmed only 26-27% of side branch lesions visually estimated to have >50% DS. Validation against physiologic measures is necessary to determine whether bifurcation QCA software has value.