Impact of Institutional Volume on Outcomes of Catheter Directed Thrombolysis in the Treatment of Acute Proximal Deep Vein Thrombosis: A 6-Year US Experience (2005-2010).

BACKGROUND: The use of catheter-directed thrombolysis (CDT) in the treatment of acute proximal lower-extremity deep vein thrombosis is increasing in the United States and has been linked to higher bleeding rates. Whether this relationship is interrelated with institution volume of CDT is unknown. METHODS AND RESULTS: The Nationwide Inpatient Sample database was used to identify all patients admitted with a principal diagnosis of proximal or inferior vena caval deep vein thrombosis and treated with CDT from 2005 to 2010. Institutions were divided into high-volume (≥6 procedures a year) and low-volume (<6 procedures a year) centers. Propensity score matching was used to create 2 matched groups for comparative analysis. A total of 90 618 patients were hospitalized for proximal lower-extremity deep vein thrombosis, and 3649 patients (4.1%) underwent CDT. In-hospital mortality was significantly lower at high-volume centers (0.6% versus 1.5%; P=0.04) with a trend toward lower intracranial hemorrhage rates compared with low-volume centers (0.4% versus 1%; P=0.07). No significant difference was seen with blood transfusion (10.4% versus 10.8%; P=0.70), gastrointestinal bleeding (1.4% versus 1.8%; P=0.35), or pulmonary embolism rates (18.4% versus 17.9%; P=0.72). Median length of stay was similar (6 days) and hospital charges were higher ($65 500 versus $75 870) at high-volume centers. CONCLUSIONS: In this observational study, we found that an increase in institutional volume of CDT was associated with lower in-hospital mortality and lower intracranial hemorrhage rates. Further studies are needed to assess whether standardization of CDT protocols across all institutions in the United States improves outcomes.

Diving medicine.

Exposure to the undersea environment has unique effects on normal physiology and can result in unique disorders that require an understanding of the effects of pressure and inert gas supersaturation on organ function and knowledge of the appropriate therapies, which can include recompression in a hyperbaric chamber. The effects of Boyle's law result in changes in volume of gas-containing spaces when exposed to the increased pressure underwater. These effects can cause middle ear and sinus injury and lung barotrauma due to lung overexpansion during ascent from depth. Disorders related to diving have unique presentations, and an understanding of the high-pressure environment is needed to properly diagnose and manage these disorders. Breathing compressed air underwater results in increased dissolved inert gas in tissues and organs. On ascent after a diving exposure, the dissolved gas can achieve a supersaturated state and can form gas bubbles in blood and tissues, with resulting tissue and organ damage. Decompression sickness can involve the musculoskeletal system, skin, inner ear, brain, and spinal cord, with characteristic signs and symptoms. Usual therapy is recompression in a hyperbaric chamber following well-established protocols. Many recreational diving candidates seek medical clearance for diving, and healthcare providers must be knowledgeable of the environmental exposure and its effects on physiologic function to properly assess individuals for fitness to dive. This review provides a basis for understanding the diving environment and its accompanying disorders and provides a basis for assessment of fitness for diving.

Carcinoid heart disease: current understanding and future directions.

Carcinoid tumors are rare and aggressive malignancies. A multitude of vasoactive agents are central to the systemic effects of these tumors. The additional burden of cardiac dysfunction heralds a steep decline in quality of life and survival. Unfortunately, by the time carcinoid syndrome surfaces clinically, the likelihood of cardiac involvement is 50%. Although medical therapies such as somatostatin analogues may provide some symptom relief, they offer no mortality benefit. On the other hand, referral to surgery following early detection has shown increased survival. The prompt recognition of this disease is therefore of the utmost importance.

Clinical utility of central venous saturation for the calculation of cardiac index in cardiac patients.

BACKGROUND: Mixed venous saturation (MVS) obtained from the distal pulmonary artery (PA) during Swan-Ganz catheterization is the criterion standard for calculating cardiac output (CO) and cardiac index (CI) with the use of the Fick method. We think that calculating CI with the use of central venous saturation (CVS) instead of PA-MVS is both feasible and accurate. Earlier studies were small, enrolled heterogeneous patient populations, and resulted in inconsistent findings. METHODS: All patients undergoing right heart catheterization from January 2011 to January 2012 in our catheterization lab with simultaneous measurements of MVS obtained from the distal PA and CVS obtained from the superior vena cava (SVC) or right atrium (RA) were included. Out of the 902 patients enrolled, we excluded patients (n = 50) who had known cardiac shunt or dialysis fistula, had duplicate medical records, or were septic. We calculated the CI with the use of the assumed Fick method using both MVS (criterion standard) and CVS (SVC or RA saturations) in the remaining 852 patients. We measured the correlation and the agreement between the 2 methods with the use of the Pearson correlation coefficient and Bland-Altman analysis. RESULTS: Totals of 112 patients with simultaneous PA and RA saturation measurements (group I) and 740 patients with simultaneous PA and SVC saturation measurements (group II) were included. We found an excellent linear correlation between SVC and PA saturation (r = 0.928) and between RA and PA saturation (r = 0.95). There was also an excellent correlation between CI calculated with the use of PA saturation and CI calculated with the use of SVC (r = 0.87) or RA (r = 0.93) saturation. The mean bias of CVS-derived CI compared with MVS-derived CI (criterion standard) was -0.1 (95% limits of agreement [LOA] -1 to +0.77) in the SVC group and -0.006 (LOA -0.68 to +0.69) in the RA group. Patients with low CI had stronger correlation and smaller bias between the 2 methods compared with those with normal or high CI. The presence of baseline hypoxemia, valvular heart disease, or acute coronary syndrome had no significant effect on the correlation or the bias between the 2 methods. CONCLUSIONS: In cardiac patients, CVS can be used as a surrogate to true MVS in the calculation of CI. This method is readily available in patients who have central venous access, and may aid in early goal-directed treatment when cardiogenic shock is suspected.

Managing hypertension in urban underserved subjects using telemedicine--a clinical trial.

BACKGROUND: We evaluated an Internet- and telephone-based telemedicine system for reducing blood pressure (BP) in underserved subjects with hypertension. METHODS: A total of 241 patients with systolic BP ≥140 mm Hg were randomized to usual care (C; n = 121) or telemedicine (T; n = 120). The T group reported BP, heart rate, weight, steps/day, and tobacco use twice weekly. The primary outcome was BP control at 6 months. RESULTS: Average age was 59.6 years, average body mass index was 33.7 kg/m(2), 79% were female, 81% were African American, 15% were white, 53% were at or below the federal poverty level, 18% were smokers, and 32% had diabetes. Six-month follow-up was achieved in 206 subjects (C: 107, T: 99). Goal BP was achieved in 52.3% in C and 54.5% in T (P = .43). Systolic BP change (C: -13.9 mm Hg, T: -18.2; P = .118) was similar in both groups. Subjects in the T group reported BP 7.7 ± 6.9 d/mo. Results were not affected by age, sex, ethnicity, education, or income. In nondiabetic T subjects, goal BP was achieved in 58.2% compared with 45.2% of diabetic T subjects (P = .024). Nondiabetic T subjects demonstrated a greater reduction in systolic BP (T: -19 ± 20 mm Hg, C: -12 ± 19 mm Hg; P = .037). No difference in BP response between C and T was noted in patients with diabetes. CONCLUSION: In hypertensive subjects, engagement in a system of care with or without telemedicine resulted in significant BP reduction. Telemedicine for nondiabetic patients resulted in a greater reduction in systolic BP compared with usual care. Telemedicine may be a useful tool for managing hypertension particularly among nondiabetic subjects.

Reducing cardiovascular disease risk in medically underserved urban and rural communities.

OBJECTIVES: The aim of this study is to evaluate methods for lowering cardiovascular disease (CVD) risk in asymptomatic urban and rural underserved subjects. BACKGROUND: Medically underserved populations are at increased CVD risk, and systems to lower CVD risk are needed. Nurse management (NM) and telemedicine (T) systems may provide low-cost solutions for this care. METHODS: We randomized 465 subjects without overt CVD, with Framingham CVD risk >10% to NM with 4 visits over 1 year, or NM plus T to facilitate weight, blood pressure (BP), and physical activity reporting. The study goal was to reduce CVD risk by 5%. RESULTS: Three hundred eighty-eight subjects completed the study. Cardiovascular disease risk fell by ≥ 5% in 32% of the NM group and 26% of the T group (P, nonsignificant). In hyperlipidemic subjects, total cholesterol decreased (NM -21.9 ± 39.4, T -22.7 ± 41.3 mg/dL) significantly. In subjects with grade II hypertension (systolic BP ≥ 160 mm Hg, 24% of subjects), both NM and T groups had a similar BP response (average study BP: NM 147.4 ± 17.5, T 145.3. ± 18.4, P is nonsignificant), and for those with grade I hypertension (37% of subjects), T had a lower average study BP compared to NM (NM 140.4 ± 16.9, T 134.6 ± 15.0, P = .058). In subjects at high risk (Framingham score ≥ 20%), risk fell 6.0% ± 9.9%; in subjects at intermediate risk (Framingham score ≥ 10, < 20), risk fell 1.3% ± 4.5% (P < .001 compared to high-risk subjects). Medication adherence was similar in both high- and intermediate-risk subjects. CONCLUSIONS: In 2 underserved populations, CVD risk was reduced by a nurse intervention; T did not add to the risk improvement. Reductions in BP and blood lipids occurred in both high- and intermediate-risk subjects with greatest reductions noted in the high-risk subjects. Frequent communication using a nurse intervention contributes to improved CVD risk in asymptomatic, underserved subjects with increased CVD risk. Telemedicine did not change the effectiveness of the nurse intervention.

Treatment of patients with intermediate cardiovascular risk: Are clinical measures enough?

AIM: Clinical measures of cardiovascular disease risk (CVD) are important tools for establishing therapy to lower CVD risk. Risk assessment has come under criticism because clinical measures can underestimate or overestimate CVD risk. We assessed CVD risk in 252 subjects without evidence of CVD to establish therapy of one or more risk factors from clinical indications. The subjects all had intermediate CVD risk using the Framingham score. RESULTS: Average age was 59.1 years. 23.8% were smokers, 59.1% were hypertensive, 65.1% had hyperlipidemia. BMI was greater than 30 kg/M(2) in 56% and diabetes was present in 43.7%. In this cohort, 86.9% required therapy for hypertension or hyperlipidemia, and this proportion increased to 95.6% when subjects with diabetes were included. Of the remaining 4.4% (11 subjects), 7 reached intermediate risk based on cigarette smoking and 4 based on age >65 years old. Among diabetics, 94/110 had another risk factor and would require statin and ACE or ARB therapy. CONCLUSIONS: Of subjects at intermediate risk for CVD, 98.4% would not require further testing to decide on therapy to lower CVD risk. Although 16 diabetic subjects had no other risk factors, current guidelines suggest that these subjects should be treated to reduce CVD risk.

Hospitalized acute exacerbation of COPD impairs flow and nitroglycerin-mediated peripheral vascular dilation.

Vascular function, as measured by flow mediated dilation (FMD) and nitroglycerin mediated dilation (NMD), is impaired in COPD. Increases in systemic inflammatory mediators during acute exacerbations of COPD (AECOPD) may further impair vascular function and may account for the increased prevalence of cardiovascular disease in COPD patients. Similarly it may account for the increased morbidity and mortality in COPD patients hospitalized with acute exacerbations. We hypothesized that FMD and NMD would be impaired during AECOPD requiring hospitalization and that vascular function would improve upon AECOPD resolution. We used FMD and NMD to evaluate vascular function in 19 patients hospitalized with AECOPD. FMD and NMD were repeated approximately three months later in 8 of these patients. In these eight patients significant improvements were observed in FMD (2.6 ± 1.5% vs 5.1 ± 2.4%, p = 0.04) and NMD (5.0 ± 2.6% vs 13.3 ± 4.5, p = 0.02) after resolution of their exacerbation. We conclude that endothelial and vascular smooth muscle function is markedly impaired during AECOPD requiring hospitalization and improves following resolution. The systemic vascular impairment that occurs during AECOPD may partially explain the observed increased in cardiac morbidity and mortality that occur in this population.

The cardiovascular system and diving risk.

Recreational scuba diving is a sport that requires a certain physical capacity, in addition to consideration of the environmental stresses produced by increased pressure, low temperature and inert gas kinetics in tissues of the body. Factors that may influence ability to dive safely include age, physical conditioning, tolerance of cold, ability to compensate for central fluid shifts induced by water immersion, and ability to manage exercise demands when heart disease might compromise exercise capacity. Patients with coronary heart disease, valvular heart disease, congenital heart disease and cardiac arrhythmias are capable of diving, but consideration must be given to the environmental factors that might interact with the cardiac disorder. Understanding of the interaction of the diving environment with various cardiac disorders is essential to providing a safe diving environment to individual divers with known heart disease.

Medical screening of recreational divers for cardiovascular disease: consensus discussion at the Divers Alert Network Fatality Workshop.

Cardiac events are responsible for a significant proportion of recreational diving fatalities. It seems inescapable that our current systems for selecting suitable recreational diver candidates and for longitudinal monitoring of diver health are failing to exclude some divers at high risk of cardiac events. Based on review of practice in parallel sporting disciplines and of the relevant literature, a series of recommendations for screening questions, identification of disqualifying conditions and risk factors, and investigation of candidates with risk factors was drafted. Recommendations for ongoing health monitoring in established divers were also generated. These recommendations were promulgated and debated among experts at a dedicated session of the Divers Alert Network Fatality Workshop. As a result, we propose a modified list of screening questions for cardiovascular disease that can be incorporated into health questionnaires administered prior to diver training. This list is confluent with the American Heart Association (AHA) preparticipation screen for athletes. The exercise stress test unmasks inducible cardiac ischemia and quantifies exercise capacity, and remains the tool of choice for evaluating diver candidates or divers with risk factors for coronary disease. An exercise capacity that allows for sustained exercise at a 6-MET intensity (possibly representing a peak capacity of 11-12 METS) is an appropriate goal for recreational divers.

Managing heart failure care using an internet-based telemedicine system.

BACKGROUND: Managing patients with heart failure (HF) is labor intensive, and follow-up is often inadequate to detect day-to-day changes that ultimately lead to decompensation. We tested the effect of an Internet-based telemedicine (T) system that provides frequent surveillance and increased communicate between HF patients and their provider on frequency of hospitalization in a cohort of patients with advanced HF. METHODS AND RESULTS: HF patients in NYHA Class II-IV were randomized to usual care (UC, n = 24) or T (T plus UC, n = 24) and followed for 1 year. Office visits, emergency department visits, hospitalizations, telephone calls, and number of Internet communications were measured over the 1-year period. Left ventricular ejection fraction (EF) was assessed by echocardiography in both groups. For T, mean age was 53.2 +/- 2.0 years (72% male, 61% Caucasian, 39% African American). For UC, mean age was 54.1 +/- 2.6 years (76% male, 72% Caucasian, 14% African American, and 14% Hispanic). HF etiologies and EF were similar in both groups. During the 12-month period, UC had 74 total phone calls to the practice, whereas T had 88 telephone calls plus 1887 telemedicine data messages (6.5 messages/patient/month). ER visits were lower in the T group (T 5, UC 12; P < .05). Hospital admissions (T 24, C 40; P = .025) and total hospital days (T 84, UC 226 days; P < .005) were lower in T. Unscheduled clinic visits (T 13, UC 13; P = NS) and scheduled clinic visits (T 78, UC 94; P = NS) were similar in both groups. CONCLUSIONS: Frequent monitoring and patient management using a telemedicine system may help to reduce hospitalizations, hospital days, and emergency department visits.

Cardiovascular disease knowledge and risk perception among underserved individuals at increased risk of cardiovascular disease.

BACKGROUND: Cardiovascular disease (CVD) risk factor awareness and knowledge are believed to be prerequisites for adopting healthy lifestyle behaviors. The purpose of this study was to examine knowledge of CVD risk factors and risk perception among individuals with high CVD risk. METHODS: The sample consisted of inner city and rural medically underserved patients at high risk of CVD. To be eligible for the trial, subjects were required to have a 10% or greater CVD risk on the Framingham risk score. Knowledge of CVD was assessed with a 29-item questionnaire created for this study. Subjects also rated their perception of risk as compared with individuals of their own sex and age. RESULTS: Data were collected from 465 subjects (mean [SD] age, 60.5 [10.1] years; mean [SD] Framingham risk score, 17.3% [9.5%]). The mean (SD) CVD knowledge score was 63.7% (14.6%), and mean (SD) level of risk perception was 0.35 (1.4). Men and women had similar Framingham risk scores, but women perceived their risk to be significantly higher than that of their male counterparts. Women were also more knowledgeable than men about CVD. Urban participants had significantly higher actual risks than did their rural counterparts (18.2% [10.7%] vs 16.0% [8.9%], respectively; P = .01) but were significantly less knowledgeable about heart disease and also perceived their risk to be lower. CONCLUSIONS: These results indicate a low perception of risk and cardiovascular knowledge especially among men and inner city residents. Innovative educational strategies are needed to increase risk factor knowledge and awareness among at-risk individuals.

Accuracy of blood pressure measurements transmitted through a telemedicine system in underserved populations.

In underserved populations, inadequate surveillance and treatment allows hypertension to persist until actual cardiovascular events occur. Thus, we developed an Internet-based telemedicine system to address the suboptimal control of hypertension and other modifiable risk factors. To minimize cost, the subjects used home monitors for blood pressure (BP) measurements and entered these values into the telemedicine system. We hypothesized that patients could accurately measure their BP and transmit these values via a telemedicine system. Inner city and rural subjects (N = 464; 42% African-American or Hispanic) with 10% or greater 10-year risk of cardiovascular disease and with treatable risk factors were randomized into two groups, control group (CG) and telemedicine group (TG). Each subject received a home sphygmomanometer with memory. The TG recorded and entered BP at least weekly. During office visits, the BP meters were downloaded and recorded BP compared to BP values transmitted via telemedicine. The telemedicine (T) BP values were similar to the meter recorded (R) values (T: systolic/diastolic BP 133.4 +/- 11.1/77.5 +/- 6.8 mm Hg, and R: systolic/diastolic BP 136.4 +/- 11.9.4/79.7 +/- 7.5 mm Hg). The percent error was <1% for both systolic (-0.02 +/- 0.04%) and diastolic (-0.03 +/- 0.04%) BP. Lastly, the telemedicine BP values were similar to the office (O) BP values for systolic and diastolic BP (T: systolic/diastolic BP 133.4 +/- 11.1/77.5 +/- 6.8 mm Hg, and O: systolic/diastolic BP 136.3 +/- 20.5/78.1 +/- 10.5 mm Hg). In underserved populations, this inexpensive approach of patients using a home monitor and entering these values into a telemedicine system provided accurate BP data.

Use of an internet-based telemedicine system to manage underserved women with gestational diabetes mellitus.

BACKGROUND: Internet technology has been proven to be a successful tool for the management of patients with multiple medical conditions. The purpose of this study was to demonstrate the feasibility of monitoring glucose control in indigent women with gestational diabetes mellitus (GDM) over the Internet. METHODS: Women with GDM were randomized to either the Internet group (n = 32) or the control group (n = 25). Patients in the Internet group were provided with computers and/or Internet access if needed. A website was established for documentation of glucose values and communication between the patient and the health care team. Women in the control group maintained paper logbooks, which were reviewed at each prenatal visit. Maternal feelings of diabetes self-efficacy were assessed at study entry and again before delivery. RESULTS: Women in the Internet group accessed the system and sent on average 21.8 (+/- 16.9) sets of data. There was no difference between the two groups in regards either fasting or post-prandial blood glucose values, although more women in the Internet group received insulin therapy (31% vs. 4%; P <0.05). There were also no significant differences in pregnancy and neonatal outcomes between the two groups. Women in the Internet group demonstrated significantly higher feelings of self-efficacy at the study's end. CONCLUSIONS: The benefit of monitoring blood glucose in indigent women with GDM via the Internet was limited by their infrequent use of the telemedicine system. Although system use was not associated with improved pregnancy outcomes, women in the telemedicine group did experience enhanced feelings of diabetes psychosocial self-efficacy.

Sex Differences in Fractional Flow Reserve-Guided Revascularization: A Nationwide Analysis.

BACKGROUND: Women with coronary artery disease are less likely to be revascularized than men based on angiography alone. Recent studies have shown that female patients have higher fractional flow reserve (FFR) values for a given severity of coronary stenosis. However, gender differences in coronary revascularization rates following FFR assessment are unknown. METHODS: The nationwide inpatient sample database was used to identify all patients who underwent FFR in the United States between January 2009 and December 2010. We used propensity score matching to compare revascularization rates and in-hospital outcomes among men and women undergoing FFR measurements. RESULTS: Among 3712 patients who underwent FFR during the study period, 1235 matched pairs of men and women were identified. The overall revascularization rates were lower in women than men (40.1% vs. 52.8%, p < 0.01). Women were less likely to undergo either percutaneous (35.2% vs. 45.6%, p < 0.01) or surgical revascularization following FFR than men (5.2% vs. 7.4%, p = 0.03). Women had a nonsignificant trend toward higher in-hospital mortality (0.8% vs. 0.5%, p = 0.32) and significantly higher rates of access site hematoma formation (2.7% vs. 0.8%, p < 0.01) compared to men. CONCLUSION: In conclusion, this large nationwide study reveals that coronary revascularization rates are significantly lower in women than in men even after functional assessment with FFR.

Sports Cardiology: Core Curriculum for Providing Cardiovascular Care to Competitive Athletes and Highly Active People.

The last few decades have seen substantial growth in the populations of competitive athletes and highly active people (CAHAP). Although vigorous physical exercise is an effective way to reduce the risk of cardiovascular (CV) disease, CAHAP remain susceptible to inherited and acquired CV disease, and may be most at risk for adverse CV outcomes during intense physical activity. Traditionally, multidisciplinary teams comprising athletic trainers, physical therapists, primary care sports medicine physicians, and orthopedic surgeons have provided clinical care for CAHAP. However, there is increasing recognition that a care team including qualified CV specialists optimizes care delivery for CAHAP. In recognition of the increasing demand for CV specialists competent in the care of CAHAP, the American College of Cardiology has recently established a Sports and Exercise Council. An important primary objective of this council is to define the essential skills necessary to practice effective sports cardiology.

Pulmonary Aspects of Exercise and Sports.

Although the lungs are a critical component of exercise performance, their response to exercise and other environmental stresses is often overlooked when evaluating pulmonary performance during high workloads. Exercise can produce capillary leakage, particularly when left atrial pressure increases related to left ventricular (LV) systolic or diastolic failure. Diastolic LV dysfunction that results in elevated left atrial pressure during exercise is particularly likely to result in pulmonary edema and capillary hemorrhage. Data from race horses, endurance athletes, and triathletes support the concept that the lungs can react to exercise and immersion stress with pulmonary edema and pulmonary hemorrhage. Immersion in water by swimmers and divers can also increase stress on pulmonary capillaries and result in pulmonary edema. Swimming-induced pulmonary edema and immersion pulmonary edema in scuba divers are well-documented events caused by the fluid shifts that occur with immersion, elevated pulmonary venous pressure during extreme exercise, and negative alveolar pressure due to inhalation resistance. Prevention strategies include avoiding extreme exercise, avoiding over hydration, and assuring that inspiratory resistance is minimized.

Can asthmatic subjects dive?

Recreational diving with self-contained underwater breathing apparatus (scuba) has grown in popularity. Asthma is a common disease with a similar prevalence in divers as in the general population. Due to theoretical concern about an increased risk for pulmonary barotrauma and decompression sickness in asthmatic divers, in the past the approach to asthmatic diver candidates was very conservative, with scuba disallowed. However, experience in the field and data in the current literature do not support this dogmatic approach. In this review the theoretical risk factors of diving with asthma, the epidemiological data and the recommended approach to the asthmatic diver candidate will be described.