Gersh, Bernard J.

In recent years, it has become apparent that coronary microvascular dysfunction plays a pivotal pathogenic role in angina pectoris. Functional and structural mechanisms can affect the physiological function of the coronary microvasculature and lead to myocardial ischemia in people without coronary atheromatous disease and also in individuals with obstructive coronary artery disease. Abnormal dilatory responses of the coronary microvessels, coronary microvascular spasm, and extravascular compressive forces have been identified as pathogenic mechanisms in both chronic and acute forms of ischemic heart disease. The condition characterized by anginal symptoms and evidence of myocardial ischemia triggered by coronary microvascular dysfunction, in the absence of obstructive coronary disease, is known as microvascular angina. The concept of microvascular angina, however, may extend further to include patients with obstructive coronary artery disease and individuals with angina after coronary revascularization or heart transplantation because coronary microvascular dysfunction contributes to myocardial ischemia in many such patients. Patients with microvascular angina constitute a sizeable proportion of all cases of stable angina undergoing diagnostic coronary angiography and of those with persisting angina after successful coronary revascularization. Coronary microvascular dysfunction is also often responsible for angina in individuals with cardiomyopathy and heart valve disease as well as acute coronary syndrome cases such as Takotsubo syndrome and myocardial infarction with no obstructive coronary artery disease. Patients with stable microvascular angina present typically with effort or rest chest pain and a reduced coronary flow reserve or microvascular spasm. This condition, which affects women and men, can markedly impair quality of life and prognosis and represents a substantial cost burden to healthcare systems and individuals alike. In recent years, progress in the diagnosis of myocardial ischemia and the use of tests to investigate functional and structural causes for a reduced coronary flow reserve and microvascular spasm have allowed the identification of an increased number of cases of microvascular angina in everyday clinical practice. Although some of the available anti-anginal drugs may be helpful, treatment of coronary microvascular dysfunction remains a major challenge. The present article discusses the fundamental role that coronary microvascular dysfunction plays in the pathogenesis of ischemic heart disease, the clinical characteristics of patients presenting with microvascular angina, and possible diagnostic and therapeutic strategies.

Objective The association with B-type natriuretic peptide (BNP), disease progression and outcomes in patients with atrial fibrillation (AF) has not been thoroughly investigated. Methods We evaluated the association between BNP levels and outcomes, including AF progression, composite outcome of major adverse cardiovascular or neurological events (MACNE) and major bleeding, via pooled logistic regression and Cox frailty models in Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II registry. AF progression was defined as either paroxysmal becoming persistent or permanent, or persistent becoming permanent at any follow-up. Results Among 13 375 patients with AF, 2797 with BNP values at baseline (median age (IQR), 72.0 (63.0–80.0) years; 43.0% women; median BNP, 238 (102–502) ng/L; 42.3% prior heart failure) were included in the models evaluating the association between BNP levels and MACNE or major bleeding. Of these, 1282 patients with paroxysmal or persistent AF at baseline were analysed in AF progression model. The likelihood of AF progression (adjusted OR, 1.11 for every 100 ng/mL; 95% CI 1.03 to 1.19) and MACNE (adjusted HR, 1.11 for every doubling in BNP values; 95% CI 1.01 to 1.22) increased with BNP concentration, while the elevated BNP values were not associated with increased risks of major bleeding. BNP values improved the risk prediction of AF progression and MACNE when added to conventional risk estimates. Conclusions BNP levels are associated with increased risk of AF progression and cardiovascular outcomes in patients with AF. Further studies are required to assess whether biomarker-based risk stratification improves patient outcomes. Clinical trial registration NCT01701817 .

Background Chronic kidney disease ( CKD ) is a common comorbidity in patients with atrial fibrillation. The presence of CKD complicates drug selection for stroke prevention and rhythm control. Methods and Results Patients enrolled in ORBIT AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) with baseline renal function and follow‐up data were included (N=9019). CKD was defined as an estimated creatinine clearance <60 mL /min. Patient characteristics were compared by CKD status, and Cox proportional hazards modeling was used to examine the association between oral anticoagulant ( OAC ) use and outcomes and antiarrhythmic drug use and outcomes stratified by CKD stages. At enrollment, 3490 (39%) patients had an estimated creatinine clearance <60 mL /min. Patients with CKD were older and had higher CHA 2 DS 2 VAS c and Anticoagulant and Risk Factors in Atrial Fibrillation (ATRIA) scores. A rhythm control strategy was selected less frequently in patients with CKD , while OAC use was lower among Stage IV and V CKD patients. After adjustment, no significant interaction was noted for OAC and CKD on all‐cause mortality ( P =0.5442) or cardiovascular death ( P =0.1233), although a trend for increased major bleeding ( P =0.0608) and stroke, systemic embolism or transient ischemic attack ( P =0.0671) was observed. No interaction was noted for antiarrhythmic drug use and CKD status on all‐cause mortality ( P =0.9706), or stroke, systemic embolism or transient ischemic attack ( P =0.4218). Conclusions Patients with atrial fibrillation and CKD are less likely to be treated with rhythm control. Patients with advanced CKD are less likely to receive OAC . Finally, outcomes with OAC in patients with advanced CKD may be materially different with higher rates of both bleeding and stroke.

Background: There are contrasting reports on the effectiveness of a concomitant intra-aortic balloon pump (IABP) in cardiogenic shock patients treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). This study sought to compare short-term mortality in patients with cardiogenic shock treated with VA-ECMO with and without IABP. Methods and Results: We reviewed the published literature from 2000 to 2018 for studies evaluating adult patients requiring VA-ECMO for cardiogenic shock with concomitant IABP. Studies reporting short-term mortality were included. Meta-analysis of the association of IABP with mortality was performed using Mantel-Haenszel models. Subgroup analyses were performed in patients with cardiogenic shock complicating acute myocardial infarction (AMI) and postcardiotomy cardiogenic shock. Twenty-two observational studies with 4653 patients were included. These studies showed high heterogeneity for the total and postcardiotomy cardiogenic shock cohorts and low heterogeneity for the AMI cohort. Short-term mortality was not significantly different in patients with and without IABP 42.1% versus 57.8%; risk ratio, 0.80; 95% CI, 0.52–1.22; P =0.30. However, concomitant IABP with VA-ECMO was associated with lower mortality in patients with AMI (50.8% versus 62.4%; risk ratio, 0.56; 95% CI, 0.46–0.67; P <0.001). There was no difference in mortality in postcardiotomy cardiogenic shock and mixed causes for cardiogenic shock. Conclusions: In cardiogenic shock patients requiring VA-ECMO support, the use of IABP did not influence mortality in the total cohort. In patients with AMI, use of IABP with VA-ECMO was associated with 18.5% lower mortality in comparison to patients on VA-ECMO alone. Further randomized studies are warranted to corroborate these observational data.

Background— The effectiveness of implantable cardioverter-defibrillators (ICDs) for primary prevention of sudden death in patients with an ejection fraction (EF) ≤35% and clinical heart failure is well established. However, outcomes after replacement of the ICD generator in patients with recovery of EF to >35% and no previous therapies are not well characterized. Methods and Results— Between 2001 and 2011, generator replacement was performed at 2 tertiary medical centers in 253 patients (mean age, 68.3±12.7 years; 82% men) who had previously undergone ICD placement for primary prevention but subsequently never received appropriate ICD therapy. EF had recovered to >35% in 72 of 253 (28%) patients at generator replacement. During median (quartiles) follow-up of 3.3 (1.8–5.3) years after generator replacement, 68 of 253 (27%) experienced appropriate ICD therapy. Patients with EF ≤35% were more likely to experience ICD therapy compared with those with EF >35% (12% versus 5% per year; hazard ratio, 3.57; P =0.001). On multivariable analysis, low EF predicted appropriate ICD therapy after generator replacement (hazard ratio, 1.96 [1.35–2.87] per 10% decrement; P =0.001). Death occurred in 25% of patients 5 years after generator replacement. Mortality was similar in patients with EF ≤35% and >35% (7% versus 5% per year; hazard ratio, 1.10; P =0.68). Atrial fibrillation (3.24 [1.63–6.43]; P <0.001) and higher blood urea nitrogen (1.28 [1.14–1.45] per increase of 10 mg/dL; P <0.001) were associated with mortality. Conclusions— Although approximately one fourth of patients with a primary prevention ICD and no previous therapy have EF >35% at the time of generator replacement, these patients continue to be at significant risk for appropriate ICD therapy (5% per year). These data may inform decisions on ICD replacement.

Background: Risks and mechanisms of extension of conservatively managed spontaneous coronary artery dissection (SCAD) remain incompletely understood. Study objectives were to (1) evaluate mechanisms of early SCAD evolution through serial angiographic analysis, and (2) determine predictors of early SCAD progression. Methods and Results: Retrospective registry study of patients with SCAD managed with an initial conservative strategy (n=240). Patients who experienced significant SCAD progression within 14 days, defined as clinical worsening plus new critical coronary obstruction on repeat angiography, were compared with remaining controls. A total of 42 of 240 (17.5%) experienced significant SCAD progression after index conservative approach; 91% by day 6. Isolated intramural hematoma (IMH) at baseline (no intimal dissection) was observed more frequently in those experiencing progression compared with controls (69.1% versus 44.4%; P =0.004). Multivariable predictors of SCAD progression included lesion severity, multivessel involvement, and isolated IMH. To investigate mechanisms of SCAD evolution, all repeat angiograms ≤14 days were compared with corresponding baselines (n=82 patient angiogram pairs). Of those with isolated IMH at baseline, 20% developed intimal dissection at repeat study. IMH was associated with greater longitudinal lesion extension (11.5 versus 2.8 mm; P =0.01), worsening Thrombolysis in Myocardial Infarction flow (−0.8 versus 0.1; P =0.003), and a nonsignificant lower rate of angiographic improvement (20.0% versus 31.3%; P =0.16) compared with the group with baseline intimal dissection. Optical coherence tomography subgroup analysis (n=17) indicated intimo-medial thickness to be lowest at the midpoint of IMH. Conclusions: Conservatively managed SCAD carries a 1:6 hazard for serious deterioration within 6 days. The risk was higher in those with isolated IMH at baseline. IMH often precedes development of intimal dissection, which has implications for mechanisms of SCAD.

Background Current American College of Cardiology/American Heart Association guidelines suggest that for patients with atrial fibrillation who are at low risk for stroke (CHA 2 DS 2 VASc=1) (or women with CHA 2 DS 2 VASc=2) a variety of treatment strategies may be considered. However, in clinical practice, patterns of treatment in these “low‐risk” patients are not well described. The objective of this analysis is to define thromboembolic event rates and to describe treatment patterns in patients with low‐risk CHA 2 DS 2 VASc scores. Methods and Results We compared characteristics, treatment strategies, and outcomes among patients with a CHA 2 DS 2 VASc=0, CHA 2 DS 2 VASc=1, females with a CHA 2 DS 2 VASc=2, and CHA 2 DS 2 VASc ≥2 in ORBIT‐AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) I & II. Compared with CHA 2 DS 2 VASc ≥2 patients (84.2%), those with a CHA 2 DS 2 VASc=0 (60.3%), 1 (69.9%), and females with a CHA 2 DS 2 VASc score=2 (72.4%) were significantly less often treated with oral anticoagulation ( P <0.0001). Stroke rates were low overall and ranged from 0 per 100 patient‐years in those with CHA 2 DS 2 VASc=0, 0.8 (95% confidence interval [CI] [0.5–1.2]) in those with CHA 2 DS 2 VASc=1, 0.8 (95% CI [0.4–1.6]) in females with a CHA 2 DS 2 VASc score=2, and 1.7 (95% CI [1.6–1.9]) in CHA 2 DS 2 VASc ≥2. All‐cause mortality (per 100 patient‐years) was highest in females with a CHA 2 DS 2 VASc score=2 (1.4) (95% CI [0.8–2.3]), compared with patients with a CHA 2 DS 2 VASc=0 (0.2) (95% CI [0.1–1.0]), and CHA 2 DS 2 VASc=1 (1.0) (95% CI [0.7–1.4]), but lower than patients with a CHA 2 DS 2 VASc ≥2 (5.7) (95% CI [5.4–6.0]). Conclusion The majority of CHA 2 DS 2 VASc=0‐1 patients are treated with oral anticoagulation. In addition, the absolute risks of death and stroke/transient ischemic attack were low among both male and females CHA 2 DS 2 VASc=0‐1 as well as among females with a CHA 2 DS 2 VASc score=2. Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT01701817.

Background The decision to initially implant an implantable cardioverter-defibrillator (ICD) is informed by robust randomized controlled trials, but no such data exist to guide the decision to replace an ICD generator. In this study, we aimed to determine outcomes after ICD generator replacement. Methods All patients with ischemic or nonischemic cardiomyopathy who underwent ICD generator replacement from 2001 to 2011 at Mayo Clinic, MN, or Beth Israel Deaconess Medical Center, MA, were included. Outcomes included (1) appropriate therapy after generator replacement and (2) death before appropriate therapy after generator replacement. Cox proportional hazards modeling was used to determine the associations between patient characteristics and outcomes. Results In 1421 patients undergoing ICD generator replacement (mean±SD age 69.6±12.1 years, 81% male), appropriate therapy occurred after replacement in 435 patients (30.6%) over a mean follow-up of 2.7±2.6 years. Associated factors included lower left ventricular ejection fraction and history of appropriate therapy before generator replacement. Death before appropriate ICD therapy occurred in 336 (23.7%) patients. Older age, lower left ventricular ejection fraction, and noncardiac comorbidities, including diabetes mellitus, chronic lung disease, peripheral vascular disease, lower hemoglobin, and lower glomerular filtration rate, were associated with greater risk of death before appropriate therapy. A progressive increase in mortality was observed with aggregation of these noncardiac comorbidities. Conclusions The decision to replace the ICD should take into consideration not only left ventricular ejection fraction and history of ventricular arrhythmias, but also comorbid illnesses that may impact the duration and the quality of life.