Contrast Ultrasound Assessment of Skeletal Muscle Recruitable Perfusion after Permanent Left Ventricular Assist Device Implantation: Implications for Functional Recovery.

BACKGROUND: In heart failure with reduced ejection fraction (HFrEF), abnormal regulation of skeletal muscle perfusion contributes to reduced exercise tolerance. The aim of this study was to test the hypothesis that improvement in functional status after permanent left ventricular assist device (LVAD) implantation in patients with HFrEF is related to improvement in muscle perfusion during work, which was measured using contrast-enhanced ultrasound (CEUS). METHODS: CEUS perfusion imaging of calf muscle at rest and during low-intensity plantar flexion exercise (20 W, 0.2 Hz) was performed in patients with HFrEF (n = 22) at baseline and 3 months after placement of permanent LVADs. Parametric analysis of CEUS data was used to quantify muscle microvascular blood flow (MBF), blood volume index, and red blood cell flux rate. For subjects alive at 3 months, comparisons were made between those with New York Heart Association functional class I or II (n = 13) versus III or IV (n = 7) status after LVAD. Subjects were followed for a median of 5.7 years for mortality. RESULTS: Echocardiographic data before and after LVAD placement and LVAD parameters were similar in subjects classified with New York Heart Association functional class I-II versus functional class III-IV after LVAD. Skeletal muscle MBF at rest and during exercise before LVAD implantation was also similar between groups. After LVAD placement, resting MBF remained similar between groups, but during exercise those with New York Heart Association functional class I or II had greater exercise MBF (111 ± 60 vs 52 ± 38 intensity units/sec, P = .03), MBF reserve (median, 4.45 [3.95 to 6.80] vs 2.22 [0.98 to 3.80]; P = .02), and percentage change in exercise MBF (median, 73% [-28% to 83%] vs -45% [-80% to 26%]; P = .03). During exercise, increases in MBF were attributable to faster microvascular flux rate, with little change in blood volume index, indicating impaired exercise-mediated microvascular recruitment. The only clinical or echocardiographic feature that correlated with post-LVAD exercise MBF was a history of diabetes mellitus. There was a trend toward better survival in patients who demonstrated improvement in muscle exercise MBF after LVAD placement (P = .05). CONCLUSIONS: CEUS perfusion imaging can quantify peripheral vascular responses to advanced therapies for HFrEF. After LVAD implantation, improvement in functional class is seen in patients with improvements in skeletal muscle exercise perfusion and flux rate, implicating a change in vasoactive substances that control resistance arteriolar tone.

Trends of Hospitalizations in the United States from 2000 to 2012 of Patients >60 Years With Aortic Valve Disease.

In recent years, there has been an increased emphasis on the diagnosis and treatment of valvular heart disease and, in particular, aortic stenosis. This has been driven in part by the development of innovative therapeutic options and by an aging patient population. We hypothesized an increase in the number of hospitalizations and the economic burden associated with aortic valve disease (AVD). Using Nationwide Inpatient Sample from 2000 to 2012, AVD-related hospitalizations were identified using International Classification of Diseases, Ninth Revision, Clinical Modification, code 424.1, as the principal discharge diagnosis. Overall AVD hospitalizations increased by 59% from 2000 to 2012. This increase was most significant in patients >80 years and those with higher burden of co-morbidities. The most frequent coexisting conditions were hypertension, heart failure, renal failure, anemia, and diabetes. Overall inhospital mortality of patients hospitalized for AVD was 3.8%, which significantly decreased from 4.5% in 2000 to 3.5% in 2012 (p <0.001). The largest decrease in mortality was seen in the subgroup of patients who had heart failure (62% reduction), higher burden of co-morbidities (58% reduction), and who were >80 years (53% reduction). There was a substantial increase in the cost of hospitalization in the last decade from $31,909 to $38,172 (p <0.001). The total annual cost for AVD hospitalization in the United States increased from $1.3 billion in 2001 to $2.1 billion in 2011 and is expected to increase to nearly 3 billion by 2020. The last decade has witnessed a significant increase in hospitalizations for AVD in the United States. The associated decrease in inhospital mortality and increase in the cost of hospitalization have considerably increased the economic burden on the public health system.

Impact of CMS coverage decision on access to transcatheter aortic valve replacement.

OBJECTIVES: To assess the impact of the Centers for Medicare and Medicaid Services (CMS) national coverage determination (NCD) on access for patients with aortic stenosis (AS) with transcatheter aortic valve replacement (TAVR) in a tertiary care center. BACKGROUND: TAVR has given hope to patients with AS who are deemed inoperable. The effects of the NCD on access to patients with AS has not been evaluated. MATERIALS AND METHODS: A total of 94 inoperable AS patients were evaluated and treated from December 2011 through June of 2012 with TAVR. Patients who underwent transfemoral (TF) vs. non-TF access were compared. The CMS NCD was released on May 1, 2012 and on July 1, 2012, the nontransfemoral access program was put on hold due to lack of reimbursement. RESULTS: Patients in the TF (n = 33) and non-TF access (n = 61) groups were similar in age (85.2 ± 6.3 vs. 84.8 ± 6.6 P = 0.74) and STS mortality (9.38 ± 5.33 vs. 7.91 ± 3.69, P = 0.074). The iliofemoral arteries were larger diameter in the TF group (7.72 ± 1.49 vs. 6.21 ± 1.78, P < 0.001) and males (7.39 ± 1.81 vs. 6.1 ± 1.61 P < 0.001). More women underwent valve implantation via non-TF access (73 vs. 23%, P = 0.03). After the NCD, 21 patients who previously qualified for non-TF TAVR would not be reimbursed by CMS. Four died soon after. CONCLUSIONS: After the NCD, the proportion of inoperable patients with severe AS that can be treated with TAVR was greatly reduced due the lack of reimbursement for TAVR via non-TF access. This effect is particularly pronounced in women. © 2014 Wiley Periodicals, Inc.