Citations

Introduction: Aortic Stenosis (AS) is a common valve disease of the adult, caused by calcification of aortic cusps. The relationship between cusp calcification and severity of AS has been established mostly in men and it is unclear whether the calcification process and its relation to AS severity is similar in women Hypothesis: We hypothesized that the physiologic relation between aortic valve calcification (AVC) load and AS severity is different in men and women and that lower calcification loads may lead to severe AS in women Methods: We prospectively performed high resolution computed tomography (CT) without contrast in 679 patients with AS (Aortic valve area (AVA) <2cm 2 , Mean gradient ≥10 mmHg) at two academic centers (Rochester, MN; Paris, France) to measure AVC scores and compare these to the hemodynamic obstruction measured by Echo-Doppler. Results: Women vs. men were older (76±11 vs 74±11, p<0.0001) with slightly higher ejection fraction (62±12 vs 59±13, p=0.001) but AS severity was similar (AVA/body surface area 0.55±0.2 vs 0.56±0.2 cm 2 /m 2 ; Peak velocity 4±1 vs 3.9±1 m/s; Mean gradient 41±21 vs 38±18 mmHg, all p≥0.1). Yet, AVC load was lower in women vs men, score absolute or normalized for LVOT area (551±383 vs 626±399 all p<0.0001). For those with severe AS (Mean gradient >40 mmHg), AVC scores were 2433±1412 in women vs 3805±1587 in men. Multivariate analysis adjusting for age, BSA, LVOT area and mean gradient, confirmed that severe AS was achieved with lower AVC load in women (all p<0.0001). Conclusions: In this large multicenter AS population, women reached similar AS severity than males for lower calcium loads, even after adjustment for lower body and LVOT size. Hence the relation between valvular calcification process and severity of AS differs in women vs. men. Thus, future studies are needed to determine the differential mechanism of aortic calcification in men and women and diagnostic consideration must be given to gender in the interpretation of AS severity by AVC load.

Background: Potentially lethal syndromes such as long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) may account for a significant number of autopsy-negative sudden unexplained deaths (SUD). Here, the spectrum and prevalence of putative LQTS-/CPVT-causative mutations in autopsy- negative SUD was determined following a cardiac channel molecular autopsy. Methods: From September 1998 to October 2010, 173 cases of SUD (106 males, 18 ± 13 years, 89% white) were referred by Medical Examiners/Coroners for a cardiac channel molecular autopsy. Using PCR, DHPLC, and DNA sequencing, a comprehensive mutational analysis of the LQTS-susceptibility genes ( KCNQ1 , KCNH2 , SCN5A, KCNE1, and KCNE2 ) and a targeted analysis of the CPVT1-associated gene ( RYR2 ) was conducted. Results: Overall, 45 putative pathogenic mutations (20 RYR2 , 11 KCNQ1 , 6 KCNH2 , 6 SCN5A , and 2 KCNE2 , absent in 400 - 700 controls, were identified in 45 (26%) autopsy negative SUD cases. The yield was greatest for those with an exercise-induced death (16/46, 35%) or a positive personal/family history of a syncope (13/25, 52%), or sudden death (9/20, 45%). Females had a higher yield (26/67, 39%) than males (19/106, 18%, p < 0.005) especially if the SUD was during adolescence (12/25, 48% females vs. 9/50, 18% males). Females were more likely to have LQTS-associated mutations (65%) while males were more likely to have CPVT1-associated mutations (58%). Among SUD victims with exercise-induced death, the yield was much higher among the 1 - 10 year olds compared to the 11 -20 year olds (females, 71% vs 14%, p<0.05; males, 60% vs 15%, p = 0.07). However for those with death during a period of sleep, the 11 - 20 year olds had a much higher yield than the 1-10 year old group (females, 75% vs 0%, p<0.01; males 18% vs 6%). Conclusions: Over one-fourth of autopsy-negative SUD may stem from LQTS and CPVT. A cardiac channel molecular autopsy should be considered as a standard part of the evaluation of autopsy-negative SUD especially among children with exercise-induced SUD, adolescent females, and those with a positive personal/family history of cardiac events. A two-tiered approach starting with the LQTS-susceptibility genes in females and the CPVT-susceptibility genes in males may be prudent.

Background: The tissue factor pathway regulates vascular structure in the adult through regulation of thrombin generation and signaling. Deletion of tissue factor pathway inhibitor (TFPI) in the mouse results in early intrauterine lethality, precluding study of vascular development. In addition, the carboxyl terminus of TFPI may have a TF-independent effect on vascular structure. We sought to determine the role of TFPI and its carboxyl terminus in vascular development of zebrafish. Methods and results: TFPI mRNA localization studies demonstrated expression in the developing kidney, gut, and vasculature of the zebrafish. We further assessed the role of TFPI in zebrafish angiogenesis, by injecting translational and splice-inhibiting morpholino (MO) oligonucleotides directed against zebrafish TFPI mRNA into embryos from the double transgenic zebrafish Tg(Fli1GFP); Tg(GATA1dsRed) expressing GFP in vascular endothelium and dsRed in erythroid cells. Knockdown of TFPI protein expression was subsequently confirmed by immunoblotting. In a dose-dependent manner, multiple non-overlapping MOs targeting the translation initiation site of TFPI independently and synergistically led to the formation of abnormally targeted intersegmental arteries which crossed somite boundaries by 48 hours post fertilization (hpf). Additionally, a plethoric caudal vein plexus with increased honeycombing was present by 24 hpf. This latter aspect of the phenotype was most striking after a MO targeted against a splice site involving the Kunitz 3 and carboxyl terminus domains of zebrafish TFPI was injected alone. Conclusions: TFPI is expressed during zebrafish development. Morpholino knockdown of TFPI expression alters both arterial and venous patterning in the developing zebrafish, indicating a fundamental role for TFPI in targeting of newly-formed blood vessels. Moreover, different domains of the TFPI protein may preferentially act on distinct vascular networks.

Introduction: Long QT Syndrome (LQTS) is a potentially lethal, but highly treatable cardiac channelopathy. Current treatment options include pharmacotherapy (mostly beta blockers), device therapy (mostly implantable cardioverter defibrillators (ICDs)), and/or left cardiac sympathetic denervation (LCSD) with the majority of patients requiring only beta blocker therapy. However, beta blockers are not without side effects and beta blocker intolerance can have a profoundly negative effect on a patient's quality of life. Heretofore, a prophylactic ICD has been utilized for the patient with LQTS who can not tolerate high dose beta blocker therapy. Here we examined the role of a prophylactic LCSD rather than an ICD for the LQTS patient with beta blocker intolerance. Methods: In this IRB-approved study, we retrospectively reviewed the electronic medical record for 58 patients (28 male (48%), mean age at diagnosis 9.6 ± 9 years (yrs), mean baseline QTc 524 ± 73 ms, 93% genotype positive) with LQTS who underwent LCSD at our institution from November 2005 through May 2011 (mean age at LCSD 14.0 ± 9.8 yrs). Results: Out of 58, 19 patients (33%; 15 female (79%) had LCSD as primary prevention because of beta blocker intolerance and were older at LQTS diagnosis (15.1 ± 8 vs 7.0 ± 9 yrs;.p=0.001), older at LCSD (20.5 ± 8 vs 10.9 ± 9 yrs; p<0.001), and had a shorter baseline QTc (493 ± 32 vs 539 ± 82 ms; p = 0.004) compared to the other 38 patients. Post-LCSD, 5/19 (26 %) had QTc-shortening of >30ms. With an average follow-up of 1.3 ± 0.8 yrs, none of these patients have experienced a post-LCSD cardiac event even though 7/19 (37%) had at least 1 LQTS-associated cardiac event. Qualitatively, there has been a dramatic improvement in quality of life following LCSD with subsequent decrease in beta blocker dose in 13 or discontinuation of beta blockers altogether in 5. Conclusions: Prophylactic LCSD may provide a beta blocker-reducing or even sparing strategy without increasing risk in carefully selected patients. However, LCSD should not be viewed as curative or an ICD-alternative for high-risk patients. Among appropriately selected patients who are failing to tolerate beta blocker therapy, LCSD may be an acceptable, quality of life improving alternative to an ICD and its associated comorbidities.

Background: Takotsubo cardiomyopathy (TTC) has emerged as a new clinical entity which has not been fully understood. Numerous case reports exist regarding association of TTC with high adrenergic state conditions like Pheochromocytoma. Our aim was to explore the association of common medical conditions with TTC. Methods: This was a cross sectional study using the National Inpatient Sample (NIS) 2007 database.TTC or Broken heart syndrome or Reversible left ventricular dysfunction following sudden emotional stress or Stress induced cardiomyopathy or Transient left ventricular apical ballooning syndrome was defined as patients discharged with any ICD code of 429.83 ( http://www.cdc.gov/nchs/data/icd9/agendasept05.pdf ). The common medical conditions were identified by appropriate ICD 9 codes Results: We indentified total 6229 discharges with any discharge diagnosis of TTC. The likelihood of common medical conditions with TTC is shown in Table 1. Conclusions: This is the first study to explore the association of common medical conditions associated with TTC on a nationwide basis. We conclude that the patient with hyperlipidemia, smoking, pulmonary hypertension, sub arachnoid hemorrhage, migraine, hyperthyroidism, collagen vascular diseases, anxiety state, and stress have higher odds of developing TTC. Further research needs to be done for better understanding the causes and pathophysiology of TTC which in turn will help risk stratification and define optimal therapy.

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthases (NOS), and is degraded primarily by dimethylarginine dimethylaminohydrolase-1 (DDAH1). While ADMA is elevated in patients with fibrocalcific aortic valve stenosis (FCAVD), is it unknown whether tissue levels of DDAH1 are altered in FCAVD, and whether systemic elevations in ADMA levels accelerate initiation and/or progression of FCAVD. In the present study, we measured expression of DDAH1 in normal and stenotic human aortic valves, and tested the hypothesis that increases in ADMA worsen hypertension and endothelial dysfunction and accelerate the initiation and progression of FCAVD in hypercholesterolemic mice. In tissue from humans with FCAVD, expression of DDAH1 was significantly increased compared to normal valve tissue (normal = 1.0 ± 0.1, FCAVD = 1.3 ± 0.1, ⋔⋔Ct method; p < 0.05). To experimentally alter DDAH1 levels, we used low density lipoprotein receptor-deficient, apolipoprotein B100-only (LA) mice that were either wild-type (D +/+ ) or heterozygous (D +/- ) for DDAH1. Blood pressure (tail cuff), aortic endothelial function (isolated organ bath), and aortic valve function (echocardiography), were measured at 3 and 6 month time points in these mice. Compared to LA-D +/+ mice, systolic arterial pressure was significantly increased in LA-D +/- mice at both 3 month (121±4 mmHg and 144±4 mmHg) and 6 months (138±6 mmHg and 148±4 mmHg). Aortic endothelial function progressively declined with prolonged hypercholesterolemia, but maximum relaxation to acetylcholine did not differ between LA-D +/+ and LA-D +/- mice at 3 or 6 months. While aortic valve function was similar between LA-D +/+ and LA-D +/- mice at 3 months (peak transvalvular velocity: 1.98±0.07 m/sec versus 1.94±0.06 m/s, respectively), aortic valve function was significantly worse in LA-D +/- (2.41±0.11 m/sec) compared to LA-D +/+ mice (2.20±0.09 m/sec) at 6 months (p < 0.05). In conclusion, our data support a working model in which increases in valvular DDAH1 levels protect against progression of FCAVD. Importantly, loss of DDAH1 in mice does not alter aortic valve function during early stages of FCAVD, but accelerates progression of FCAVD independently of changes in endothelial function.

Background: Regadenoson is a selective A2A receptor agonist that is administered as a fixed dose bolus with rapid onset (∼30 sec), and short duration (∼2-4 min) of action. The aim of this study was to evaluate the feasibility of real-time myocardial contrast echocardiography (MCE) for quantification of coronary flow reserve (CFR) in healthy humans during regadenoson vasodilator stress. Methods: Fifteen subjects [3 males, age: 45.8±5.2 years, BMI 23.8±2.3 kg/m2] with normal LV wall motion and no CAD underwent real-time MCE. Three standard apical LV views were acquired during a continuous intravenous (IV) infusion of Definity (1.3 ml in 60 cc 0.9% saline at 200 ml/hr) at rest and during vasodilator stress (regadenoson 400 ug IV bolus). Following transient microbubble destruction, microbubble velocity (β, sec -1 ), myocardial blood volume (A, dB) and myocardial blood flow (MBF, dB/sec) were determined. Videodensitometric quantification using a 16-segment model at end-systole was performed off-line. Results: Quantification of reserve parameters was feasible in all (15/15) patients, 188/240 segments (78%)[82%, 80% and 70% of 4-, 2-, 3-chambers apical views] and 43/45 (95%) coronary territories [one each of Cx and RCA territories were not feasible]. Augmentation from baseline to vasodilator stress was observed for both ß (s -1 ) [0.65± 0.25 vs 0.79± 0.21, P=0.031] and MBF (dB/sec) [2.85± 1.43 vs 4.65± 2.06, P= 0.002], however A (dB) did not change [06.62± 2.57 vs 6.79±2.1, P=0.463]. CFR measurements from all views were similar (Fig 1). There was no significant difference between CFR measured in the 3 coronary territories, although some heterogeneity was noted in the posterior circulation CFR (Fig 2). Conclusion: Real-time MCE during Regadenoson vasodilator stress is feasible, and is a useful technique for the rapid noninvasive quantification of CFR in healthy humans.

Introduction/Purpose: To examine trends in patient presentation, diagnosis and outcomes of acute aortic dissection over 15 years since the original report from the International Registry of Acute Aortic Dissection (IRAD). Methods: Patient data were collected at 28 international referral centers from 1996 up to the present. Trends were analyzed among 3275 patients divided according to date of enrollment into 6 equal groups and by Type: A (n=2110) or B (n=1165). Results: There was no change over time in the presenting complaints of severe or worst ever pain for Type A and Type B (90% and 96%, respectively), or in the incidence of chest pain ( 80% in Type A and 70% in Type B, respectively), with considerable overlap in chest vs. back pain between types. The report of pulse deficits did not change over time, present in 30% of Type A patients. Normal chest X-ray on presentation increased in Type A acute aortic dissection (AoD) from 13.7% to 31.3% over time (p-value for trend <0.001). In Type B the report of normal chest X-ray increased from 19.9% to 40.9% (p-value for trend <0.001). There were significant trends in initial imaging modalities for Type A: increased use of CT (from 49.4% to 71.6%, p-value for trend <0.001) and decreased use of TEE (from 45.3% to 25.4%, p-value for trend <0.001). For Type B, use of CT increased from 77.2% to 88.4% (p-value for trend .013). A decrease in overall mortality over time was significant for both Type A and Type B patients (see graph). Surgical mortality in Type A patients fell from 25.3% to 16.5% (p-value for trend 0 .003). Conclusions: No significant difference was seen over time in pain severity, chest pain, and presence of pulse deficits. The incidences of a normal chest X-ray, originally thought to be uncommon in dissection cases, increased over time to 30% in Type A and 40% in Type B AoD. Use of CT as the initial imaging modality increased for both Type A and Type B. Lastly, a significant decrease in overall mortality was seen for both Type A and Type B patients.

Objective : Practice analysis of cardiac surgical service lines suggested that, for patients having routine cardiac surgery, standardization of care processes in the ICU could reduce cost and improve outcomes. We tested this hypothesis in a large surgical practice. Methods : Patients eligible for a standardized care pathway were prospectively identified preoperatively. ICU protocol development and practice redesign occurred in 2009 with implementation in 2010. In the ICU, all major process steps to recovery were managed by tiered and integrated protocols whereby care advancement is the default if clinical criteria are met. We compared outcomes of patients managed by protocol to those managed by standard care. ICU metrics (time intubated, drip weaning, length of stay) were benchmarked against a sample of 65 CABG patients from 2008. Return to ICU and to OR for standardized care patients were compared to concurrent patients under routine care. We report on all patients having cardiac surgery for 12 months beginning March 2010. Findings : Over 12 months, the ICU care of 1289 patients followed standardized tiered protocols, while 1309 patients were managed by standard care. After implementation of standardized protocols, ICU metrics improved in protocol patients relative to 2008 (2010 versus 2008): mean intubation time in hours (7.4 vs 11.6), mean time on hemodynamic drips in hours (16.2 vs 25.3), average ICU length of stay in hours (25.1 vs 35.9). The safety of protocol based care is demonstrated by lower rates of return to ICU and to OR among patients under protocol vs non-protocol: return to OR (1.8% vs 8.9%), return to ICU (1.6% vs 6.2%). Conclusions: With proper patient selection and rigorous protocols that make care advancement the default, cardiac surgical care in the ICU can be standardized and clinical metrics improved. The safety of this strategy is demonstrated by very low rates of return to OR or ICU. This practice model is translatable to other ICU practices.

Objective: To determine if the implementation of smoke-free workplace laws reduced the incidence of the acute coronary events including myocardial infarction (MI) and sudden cardiac death (SCD). Background: Nonsmokers chronically exposed to second-hand smoke (SHS) are at increased risk of death from heart disease. However, a nonlinear dose relationship exists between SHS exposure and coronary heart disease (CHD) such that the relative risk of CHD is 1.31 for nonsmokers and 1.78 for smokers. Reductions in admissions for MI in locales where smoke-free workplace laws have been implemented have been observed, but none have assessed SCD. On January 1, 2002, a smoke-free restaurant law (Ordinance #1) was implemented in Olmsted County, Minnesota, and on October 1, 2007, all workplaces became smoke-free (Ordinance #2). Methods: Under the auspices of the Rochester Epidemiology Project, we measured the incidence of MI and SCD during the 18-month calendar period before and after implementation of each smoke-free ordinance. All MI were validated using biomarkers, cardiac pain, and Minnesota coding of the ECG. SCD was defined as out-of-hospital deaths assigned to CHD (ICD-9 codes 410 through 414). Results: For the overall study period of the 18 months before the implementation of the smoke-free restaurant ordinance and 18 months after the implementation of the smoke-free workplace ordinance, we observed a 45% decline in the incidence for MI (p <0.01) and a 50% decline in the incidence for SCD (p <0.01). See Table. During this same period, the prevalence of hypertension, diabetes, hypercholesterolemia, and obesity either remained constant or increased while the prevalence of smoking among adults declined by 23% (22% to 17%). Conclusion: In the Olmsted County population, substantial declines in the incidence of MI and SCD were observed after smoke-free laws were implemented. Smoke-free workplace laws may not only be associated with a decrease in MI but SCD as well.