[Show abstract][Hide abstract] ABSTRACT: Introduction:
Bileaflet mitral valve prolapse (BiMVP) is common among survivors of otherwise unexplained sudden cardiac death, but prognostic implications of BiMVP are unknown. This study evaluated whether patients with BiMVP are at higher risk for ventricular dysrhythmias, ICD placement, or death compared to controls with either single-leaflet mitral valve prolapse (SiMVP) or no mitral valve prolapse (MVP).
Methods and results:
This retrospective, matched cohort study included 18,786 patients who underwent echocardiography at Mayo Clinic between June 1990 and September 2014. The study included three cohorts: BiMVP, SiMVP, and controls without MVP. We assessed rates of ventricular dysrhythmias, ICD placement, and all-cause mortality between groups. BiMVP was associated with higher rates of ventricular tachycardia compared to SiMVP and controls (adjusted HR 1.48 [1.14-1.92], p = 0.003 and 1.40 [1.04-1.88], p = 0.026 respectively); however, there were no statistically significant differences in rates of ventricular fibrillation/cardiac arrest or ICD placement between groups. BiMVP was associated with a lower rate of all-cause mortality compared to SiMVP and controls (adjusted HR 0.86 [0.79-0.94], p = 0.0008, and 0.55 [0.50-0.60], p < 0.0001, respectively).
Although BiMVP is associated with ventricular tachycardia, it is not associated with an increased risk of cardiac arrest/ventricular fibrillation or ICD implantation and is, paradoxically, associated with a better survival compared to SiMVP or matched controls. The findings suggest that, despite its association with ventricular tachycardia, BiMVP in the absence of other risk factors does not seem to portend a poor prognosis at the population level. This article is protected by copyright. All rights reserved.
No preview · Article · Jan 2016 · Journal of Cardiovascular Electrophysiology
[Show abstract][Hide abstract] ABSTRACT: Background:
We recently reported that normal aldosterone levels are associated with cardiovascular, renal, and metabolic disease in a sample of the US general community (Visit 1). For the current analyses we used the same cohort in a new 4-year follow-up study (Visit 2).
Methods and results:
We measured aldosterone at Visit 1 and analyzed its predictive role for new diseases at Visit 2 (n=1140). We measured aldosterone at Visit 2 and investigated its associations with disease at Visit 2 (n=1368). We analyzed aldosterone continuously and we also dichotomized the variable as whether subjects were in the third tertile versus second and first tertiles. As continuous variable at Visit 1, aldosterone predicted new onset hypertension (HTN) (OR=1.36, CI=1.13-1.63, P=0.001), central obesity (OR=1.36, CI=1.07-1.73, P=0.011), and use of lipid-lowering drugs (OR=1.25, CI=1.05-1.48, P=0.012) at Visit 2, after adjustment for age, sex, and body mass index. When in the third tertile (8.5-88.6 ng/dL), aldosterone predicted type 2 diabetes (T2DM, OR=1.96, CI=1.03-3.70, P=0.039). At Visit 2, aldosterone remained associated with HTN, obesity, and chronic kidney disease (CKD), as reported for Visit 1. However, aldosterone was not associated with heart failure (HF) at Visit 1 and 2, nor was aldosterone a predictor of HF between visits.
Aldosterone predicts new HTN, central obesity, T2DM, and use of lipid-lowering drugs in the general community and remains associated with HTN, obesity, and CKD over 4 years. Aldosterone is not associated nor predicts HF. Further studies are warranted to evaluate aldosterone as therapeutic target in the general community.
Preview · Article · Dec 2015 · Journal of the American Heart Association
[Show abstract][Hide abstract] ABSTRACT: Background:
The recent report that appropriately performed echocardiographic examinations result in active changes in management in only one third of patients has challenged the validity of current appropriate use criteria. Limited information exists about the clinical importance of transthoracic echocardiography (TTE) to guide management and rule out important alternative pathology.
The clinical impact of inpatient TTE performed at the Mayo Clinic over a 20-week period between October 14, 2013, and March 3, 2014, was investigated. Studies were included if they were ordered within 72 hours of admission, and treating physicians participated in a real-time survey regarding the clinical importance of TTE. Appropriate use was determined by two independent investigators, with differences adjudicated by a third investigator. Clinical impact was derived from physicians' survey responses and independently confirmed by chart review.
Of the 539 transthoracic echocardiographic examinations included in this study, 512 (95%) were appropriate, 16 (3%) may be appropriate and 11 (2%) rarely appropriate. Although only 48% of participating physicians actively changed management on the basis of findings on TTE, 97% responded that TTE answered their clinical questions, and 95% would still order TTE in similar clinical contexts.
Most early inpatient transthoracic echocardiographic studies at our institution were appropriate and answered specific clinical questions important for management decisions in the opinion of the treating physician. Confirming a plan of care already in place and ruling out alternative pathology may be as important clinically as uncovering new findings or changing management.
No preview · Article · Dec 2015 · Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography
[Show abstract][Hide abstract] ABSTRACT: Frailty is prevalent in patients with cardiovascular disease, but few studies have evaluated relations between frailty and echocardiographically determined cardiac indexes. To assess the prevalence of frailty and its association with echocardiographic characteristics, we prospectively measured frailty in 257 patients ≥65 years who underwent echocardiography (transthoracic echocardiography [TTE]) from June 2012 to February 2013. Deficits of weight loss, exhaustion, physical activity, gait speed, and handgrip strength were used to categorize patients as frail (≥3 features), intermediately frail (1 or 2 features), or nonfrail (0 features). Pearson correlation was used to examine bivariate associations between TTE variables and frailty. Kaplan-Meier methods were used to estimate overall survival based on frailty status. A multivariable model was used to examine TTE indexes associated with frailty while accounting for age and baseline cardiac co-morbidities. Of the 257 patients studied, 40 (15.6%) were nonfrail, 167 (65.0%) intermediately frail, and 50 (19.4%) frail. Left atrial volume (r = 0.14; p = 0.03), stroke volume (r = -0.19; p <0.01), E/A ratio (r = 0.26; p <0.001), and pulmonary artery systolic pressure (r = 0.33; p <0.001) correlated with fraility. After age and baseline cardiac comorbidities were accounted for, larger left atrial volumes, lower stroke volumes, and higher pulmonary artery systolic pressures remained independently associated with frailty. Frail patients had worse survival compared with nonfrail and intermediately frail patients (p = 0.016 by log-rank). In conclusion, 1/5 of older patients who underwent clinically indicated TTE were frail, with worse survival and a unique fingerprint of TTE findings distinguishing them from nonfrail patients.
No preview · Article · Sep 2015 · The American journal of cardiology
[Show abstract][Hide abstract] ABSTRACT: Aims:
Blood pressure (BP) responses during dobutamine stress echocardiography (DSE) have not been systematically studied. Consequently, it is not known what constitutes a normal or an abnormal BP response to dobutamine stress. We sought to define the typical BP response during DSE of patients not known to have cardiovascular disease.
Methods and results:
Of 24 134 patients who underwent DSE from November 2003 to December 2012 at Mayo Clinic, Rochester, MN, 2968 were selected for inclusion in this retrospective study. Excluded were patients with a history of hypertension, diabetes, or coronary artery disease, and those taking vasoactive medications. Patients who had baseline and/or stress-induced wall motion abnormalities were also excluded. The distribution of the study population's BP responses during DSE was Gaussian; we defined cut-point values for normative BP responses at 2 SD for each decade of age and for the whole study population. During DSE, systolic BP (SBP) increased from baseline to peak stress (Δ +2.9 ± 24 mmHg, P < 0.0001) and diastolic BP (DBP) decreased (Δ -7.4 ± 14 mmHg). BP changes were age and sex dependent; men and younger patients had greater ΔSBP and lesser ΔDBP, compared with women and older patients. Patients who received atropine had higher peak BP values than patients who did not receive atropine, due to greater ΔSBP (+7.4 ± 26 vs. -0.5 ± 22 mmHg, P < 0.0001) and lesser ΔDBP (-4 ± 14 vs. -9.7 ± 12 mmHg, P < 0.0001). This atropine effect was present in men and women, and was more pronounced in younger patients. The normative peak SBP values ranged from 82 to 182 mmHg.
BP responses during DSE vary and depend on patients' age, gender, and the use of atropine. We describe the typical BP responses seen during DSE and report normative reference values, which can be used for defining normal and abnormal BP responses to dobutamine stress.
No preview · Article · Jul 2015 · European Heart Journal Cardiovascular Imaging
[Show abstract][Hide abstract] ABSTRACT: Percent mammographic density (PD) estimates the proportion of stromal, fat, and epithelial breast tissues on the mammogram image. Adjusted for age and body mass index (BMI), PD is one of the strongest risk factors for breast cancer . Inherited factors are hypothesized to explain between 30 and 60% of the variance in this trait [2-5]. However, previously identified common genetic variants account for less than 6% of the variance in PD, leaving much of the genetic contribution to this trait unexplained. We performed the first study to examine whether germline copy number variation (CNV) are associated with PD. Two genome-wide association studies (GWAS) of percent density conducted on the Illumina 660W-Quad were used to identify and replicate the association between candidate CNVs and PD: the Minnesota Breast Cancer Family Study (MBCFS) and controls from the Mayo Venous Thromboembolism (Mayo VTE) Case-Control Study, with 585 and 328 women, respectively. Linear models were utilized to examine the association of each probe with PD, adjusted for age, menopausal status and BMI. Segmentation was subsequently performed on the probe-level test statistics to identify candidate CNV regions that were associated with PD.
Sixty-one probes from five chromosomal regions [3q26.1 (2 regions), 8q24.22, 11p15.3, and 17q22] were significantly associated with PD in MBCFS (p-values <0.0001). A CNV at 3q26.1 showed the greatest evidence for association with PD; a region without any known SNPs. Conversely, the CNV at 17q22 was largely due to the association between SNPs and PD in the region. SNPs in the 8q24.22 region have been shown to be associated with risk of many cancers; however, SNPs in this region were not responsible for the observed CNV association. While we were unable to replicate the associations with PD, two of the five CNVs (3q26.1 and 11p15.3) were also observed in the Mayo VTE controls.
CNVs may help to explain some of the variability in PD that is currently unexplained by SNPs. While we were able to replicate the existence of two CNVs across the two GWAS studies, we were unable to replicate the associations with PD. Even so, the proximity of the identified CNV regions to loci known to be associated with breast cancer risk suggests further investigation and potentially shared genetic mechanisms underlying the PD and breast cancer association.
Full-text · Article · Jul 2015 · BMC Research Notes
[Show abstract][Hide abstract] ABSTRACT: Among patients with severe aortic stenosis (sAS) and preserved LVEF, those with low-flow, low-gradient sAS (LFLG-sAS) have an adverse prognosis. It has been proposed that LFLG-sAS represents an end-stage point of sAS, but longitudinal information has not been described. The aim was to determine whether LFLG-sAS represents an end-stage consequence of normal-flow, high-gradient sAS (NFHG-sAS) or a different entity.
From our transthoracic echocardiogram (TTE) database, we identified patients with sAS (aortic valve area <1 cm(2)) and preserved LVEF (≥50%), and from these, patients with LFLG-sAS (stroke volume index <35 mL/m(2) and mean transvalvular gradient <40 mm Hg) who had ≥1 additional TTE within five years prior to the index TTE. Patients were age/sex/date matched 2:1 with patients with NFHG-sAS and normal-flow, low-gradient (NFLG)-sAS who also had ≥1 TTE. Included were 1203 TTEs (383 index studies and 820 preceding studies).
In 78 patients with LFLG-sAS, an HG stage preceded the index TTE in only 4 (5%). During the five years preceding the index TTE, patients with LFLG-sAS developed increasing relative wall thickness (0.42 to 0.49; p<0.001) without change in LV mass index. Patients with NFHG-sAS had a marked increase in LV mass index (87 to 115 g/m(2); p<0.001). Patients with LFLG-sAS demonstrated the greatest reduction in LV end-diastolic diameters (-3 vs -1 for NFLG-sAS vs +2 mm for NFHG-sAS; p=0.001), deceleration time (-55 vs -3 vs +3 ms, respectively; p<0.01) and LVEF (-4 vs 0 vs 0%, respectively; p=0.01).
LFLG-sAS is a distinct presentation of sAS preceded by a unique remodelling pathway and is uncommonly preceded by an HG stage.
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
No preview · Article · Mar 2015 · Heart (British Cardiac Society)