Cardiology

Xenogiannis, I., D. Karmpaliotis, K. Alaswad, F. A. Jaffer, R. W. Yeh, M. Patel, E. Mahmud, J. W. Choi, M. N. Burke, A. H. Doing, P. Dattilo, C. Toma, A. J. C. Smith, B. Uretsky, O. Krestyaninov, D. Khelimskii, E. Holper, S. Potluri . . . and E. S. Brilakis (2019). “Usefulness of Atherectomy in Chronic Total Occlusion Interventions (from the PROGRESS-CTO Registry).” Am J Cardiol 123(9): 1422-1428.

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There is limited data on the use of atherectomy during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We compared the clinical and procedural characteristics and outcomes of CTO PCIs performed with or without atherectomy in a contemporary multicenter CTO PCI registry. Between 2012 and 2018, 3,607 CTO PCIs were performed at 21 participating centers. Atherectomy was used in 117 (3.2%) cases: rotational atherectomy in 105 cases, orbital atherectomy in 8, and both in 4 cases. Patients in whom atherectomy was used, were older (68 +/- 8 vs 64 +/- 10 years, p <0.0001) and had higher Japan-chronic total occlusion score (3.0 +/- 1.2 vs 2.4 +/- 1.3, p <0.0001). CTO PCI cases in which atherectomy was used had similar technical (91% vs 87%, p=0.240) and procedural (90% vs 85%, p=0.159) success and in-hospital major adverse cardiac event (4% vs 3%, p=0.382) rates. However, atherectomy cases were associated with higher rates of donor vessel injury (4% vs 1%, p=0.031), tamponade requiring pericardiocentesis (2.6% vs 0.4%, p=0.012) and more often required use of a left ventricular assist device (9% vs 5%, p=0.031). Atherectomy cases were associated with longer procedural duration (196 [141, 247] vs 119 [76, 180] minutes, p <0.0001), and higher patient air kerma radiation dose (3.6 [2.5, 5.6] vs 2.8 [1.6, 4.7] Gray, p=0.001). In conclusion, atherectomy is currently performed in approximately 3% of CTO PCI cases and is associated with similar technical and procedural success and overall major adverse cardiac event rates, but higher risk for donor vessel injury and tamponade.

Packer, M. and P. A. Grayburn (2019). “Neurohormonal and Transcatheter Repair Strategies for Proportionate and Disproportionate Functional Mitral Regurgitation in Heart Failure.” JACC Heart Fail May 3. [Epub ahead of print].

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Functional mitral regurgitation (MR) is present to varying degrees in most patients with chronic heart failure (HF) and left ventricular (LV) systolic, and in ~ 30% its magnitude is hemodynamically meaningful. A critical determinant of MR in these patients is the degree of LV dilatation. Remodeling and enlargement of the LV leads to displacement of the papillary muscles and widening and flattening of the mitral annulus, which (together with a reduction in closing forces) impairs the coaptation of the mitral valve (MV) leaflets. However, independent of LV end-diastolic volume (LVEDV), ventricular dyssynchrony contributes importantly to functional MR. In patients with meaningful QRS prolongation, dyssynchrony causes unequal contraction of papillary muscle bearing walls, preventing coordinated closure of the MV leaflets; amelioration of the conduction delay by cardiac resynchronization reduces MR. Additionally, irrespective of the presence of electric conduction delay, localized LV remodeling can cause apical and posterior displacement of the papillary muscles and dysschronous contraction of the leaflet-supporting structures independent of global LV dysfunction. (Excerpt from text of article-in-press, not paginated; no abstract available.)

Packer, M. and P. A. Grayburn (2019). “Contrasting Effects of Pharmacological, Procedural and Surgical Interventions on Proportionate and Disproportionate Functional Mitral Regurgitation in Chronic Heart Failure.” Circulation May 1. [Epub ahead of print].

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Two distinct pathways can lead to functional mitral regurgitation (MR) in patients with chronic heart failure and a reduced ejection fraction. When remodeling and enlargement of the left ventricle (LV) causes annular dilatation and tethering of the mitral valve leaflets, there is a linear relationship between LV end-diastolic volume and the effective regurgitant orifice area (EROA) of the mitral valve. These patients – designated as having proportionate MR – respond favorably to treatments that lead to reversal of LV remodeling and a decrease in LV volumes (e.g., neurohormonal antagonists and LV assist devices), but they may not benefit from interventions that are directed only at the mitral valve leaflets (e.g., transcatheter mitral valve repair). In contrast, when ventricular dyssynchrony causes functional MR due to unequal contraction of the papillary muscles, the magnitude of regurgitation is greater than that predicted by LV volumes. These patients – designated as having severe but disproportionate MR – respond favorably to treatments that are directed to the mitral valve leaflets or its supporting structures (e.g., cardiac resynchronization or transcatheter mitral valve repair), but they may derive little benefit from interventions that act only to reduce LV cavity size (e.g., pharmacological treatments). This novel conceptual framework reflects the important interplay between LV geometry and mitral valve function in determining the clinical presentation of patients, and it allows characterization of the determinants of functional MR to guide the most appropriate therapy in the clinical setting.

Packer, M. (2019). “Is Any Patient With Chronic Heart Failure Receiving the Right Dose of the Right Beta-Blocker in Primary Care?” Am J Med Apr 12. [Epub ahead of print].

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Are physicians prescribing the right beta-blockers in the right way to patients with chronic heart failure and a reduced ejection fraction? Beta-blockers carry the strongest possible level of recommendations in guideline documents throughout the world. Yet, numerous surveys have shown that this class of drugs is greatly underutilized in clinical practice, particularly amongst primary care physicians in the US. In the most recently published survey, amongst primary care physicians, fewer than 10% of patients with heart failure who had no contraindication to beta-blockade and should have been treated with a beta-blocker actually were prescribed an evidence-based beta-blocker at the right dose. The news might even be worse, because the survey did not evaluate whether the use of these drugs in patients with atrial fibrillation was appropriate. Internists and family physicians are responsible for the care of most patients with chronic heart failure in the United States. If they are not prescribing life-saving drugs in the right manner, then millions of people with a highly treatable disease and highly preventable cause of death are receiving suboptimal therapy. The benefits of beta-blockers are remarkable and not controversial. The strongest possible evidence supporting their widespread use has been available to the clinical community for more than 15 years. Furthermore, the recommended formulations are generic and inexpensive and do not require preauthorization or complicated preapprovals. It is time for primary care organizations to sound the alarm. Heart failure is the most common, most serious and most responsive disorder that community-based practitioners can treat without the need for complex testing or referral for subspecialist care. What are we waiting for? (Excerpt from text of article-in-press, not paginated; no abstract available.)

Packer, M. (2019). “Disproportionate functional mitral regurgitation: a new therapeutic target in patients with heart failure and a reduced ejection fraction.” Eur J Heart Fail Apr 24. Epub ahead of print].

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Patients with chronic heart failure and a reduced ejection fraction who have severe and disproportionate mitral regurgitation (MR) are likely to experience important clinical consequences resulting from the haemodynamic stresses imposed by the regurgitant lesion, and the severity of MR is not likely to be reduced by conventional therapy with neurohormonal antagonists, even when administered in maximally tolerated doses. Such patients should first be treated with cardiac resynchronization (if they qualify for the procedure), and non‐candidates and non‐responders should be seriously considered for transcatheter mitral valve repair. Therefore, when treating heart failure with a reduced ejection fraction, it is now time for physicians to identify patients who also have severe and disproportionate MR, because they require specialized procedures beyond optimal pharmacological therapy. (Excerpt from text, p. 2-3; no abstract available.)