Lifestyle modification interventions differing in intensity and dietary stringency improve insulin resistance through changes in lipoprotein profiles.

OBJECTIVE: Metabolic dysfunction characterized by insulin resistance (IR) is an important risk factor for type-2 diabetes and coronary artery disease (CAD). The aim of this study was to determine if clinical lifestyle interventions differing in scope and intensity improve IR, defined by the lipoprotein IR (LPIR) score, in individuals differing in the severity of metabolic dysfunction. METHODS: Subjects with diagnosed type-2 diabetes, CAD or significant risk factors participated in one of two clinical lifestyle modification interventions: (i) intensive non-randomized programme with a strict vegetarian diet (n = 90 participants, 90 matched controls) or (ii) moderate randomized trial following a Mediterranean-style diet (n = 89 subjects, 58 controls). On-treatment and intention-to-treat analyses assessed changes over 1 year in LPIR, lipoprotein profiles and metabolic risk factors in intervention participants and controls in both programmes. RESULTS: In the on-treatment analysis, both interventions led to weight loss: [-8.9% (95% CI, -10.3 to -7.4), intensive programme; -2.8% (95% CI, -3.8 to -1.9), moderate programme; adjusted P < 0.001] and a decrease in the LPIR score [-13.3% (95% CI, -18.2 to -8.3), intensive; -8.8% (95% CI, -12.9 to -4.7), moderate; adjusted P < 0.01] compared with respective controls. Of the six lipoprotein parameters comprising LPIR, only large very-low-density lipoprotein particle concentrations decreased significantly in participants compared with controls in both programmes [-26.3% (95% CI, -43.0 to -9.6), intensive; -14.2% (95% CI, -27.4 to -1.0), moderate; P < 0.05]. Intention-to-treat analysis confirmed and strengthened the primary results. CONCLUSION: A stringent lifestyle modification intervention with a vegetarian diet and a moderate lifestyle modification intervention following a Mediterranean diet were both effective for improving IR defined by the LPIR score.

Cardiometabolic risk reduction in an intensive cardiovascular health program.

BACKGROUND AND AIMS: Insulin and leptin are important markers of insulin resistance and vascular inflammation in metabolic and cardiovascular diseases. This study evaluated changes in circulating levels of insulin and leptin during a cardiovascular health program to improve our understanding of cardiometabolic risk reduction. METHODS AND RESULTS: Participants (n=76) completed a prospective, nonrandomized program designed to stabilize or reverse progression of coronary artery disease through dietary changes, exercise, stress management, and group support. Controls (n=76) were matched to participants based on age, gender, and disease status. Traditional cardiovascular risk factors were assessed at baseline, 12 weeks, and 52 weeks by standard methods. Dietary data were collected by 72-h recall and evaluated by Food Processor® v8.4.0. Ultrasensitive insulin and leptin levels were measured by radioimmunoassay. Participants successfully reduced their total caloric intake from >2000 calories per day to ≈ 1700 calories per day (p<0.05 compared to controls), lowered daily fat intake by >60% (p<0.001 compared to controls), and increased carbohydrate intake by >30% (p<0.001). Repeated-measures ANOVA indicated significant beneficial changes (p<0.001 compared to controls) in plasma insulin (-19%) and leptin (-33%) during the lifestyle program, as well as improvement in traditional cardiovascular risk factors. Response was similar between men and women for most risk factors and was not markedly influenced by medication use. CONCLUSION: Lifestyle changes focusing on diet, physical activity, and stress reduction can successfully modify both cardiovascular and metabolic risk factors, with the potential to mediate cardiometabolic risk through beneficial anti-inflammatory and anti-oxidative effects on the vasculature.

Cleft posterior mitral valve leaflet associated with counterclockwise papillary muscle malrotation.

Isolated clefting of the posterior mitral valve leaflet is an uncommon congenital malformation. We report a case of cleft posterior mitral valve leaflet with counterclockwise papillary muscle malrotation. Similar abnormalities in papillary muscle position have been described in association with atrioventricular septal defect but have not been previously reported accompanying isolated clefting of the posterior mitral valve leaflet.

C-reactive protein is not associated with the presence or extent of calcified subclinical atherosclerosis.

BACKGROUND: Both high-sensitivity C-reactive protein (hsCRP) and electron beam computed tomography (EBCT) coronary artery calcification (CAC) are valid markers of cardiovascular risk. It is unknown whether hsCRP is a marker of atherosclerotic burden or whether it reflects a process (eg, inflammatory fibrous cap degradation) leading to acute coronary events. METHODS: A nested case-control study was performed of 188 men enrolled in the Prospective Army Coronary Calcium study. The serum hsCRP levels (latex agglutination assay) were evaluated in subjects with CAC (CAC score >0, n = 94) and compared with age- and smoking status-matched control subjects (CAC score 0, n = 94). RESULTS: Levels of hsCRP in the highest quartile were related to the following coronary risk factors: smoking status, low-density lipoprotein cholesterol, body mass index, glycosylated hemoglobin, fibrinogen, and homocysteine. The mean hsCRP level was similar in cases (+CAC, 0.20 +/- 0.22 mg/dL) and controls (-CAC, 0.19 +/- 0.21 mg/dL; P =.81) and was unrelated to the log-transformed CAC score (r < 0.01, P =.91). Multivariable analysis controlling for standard risk factors, aspirin, and statin therapy found only that low-density lipoprotein cholesterol was related to CAC. CONCLUSIONS: Despite associations with standard and emerging cardiovascular risk factors, hsCRP is unrelated to the presence and extent of calcified subclinical atherosclerosis. This implies that CAC (a disease marker) and hsCRP (a process marker) may be complementary for the prediction of cardiovascular risk.

Observer bias in the interpretation of dobutamine stress echocardiography.

BACKGROUND AND HYPOTHESIS: Blinded image analysis is typically utilized in published studies evaluating the accuracy of dobutamine stress echocardiography (DSE). However, in clinical settings, practical considerations may limit the use of blinded interpretations and thus the potential for observer bias arises. This study evaluated the relationships between clinical and blinded interpretations of DSE. METHODS: Wall motion analysis from clinical and blinded DSE interpretations were compared and factors associated with their concordance were investigated in 115 consecutive patients with known or suspected coronary artery disease. RESULTS: Clinical and blinded interpretations agreed on the presence or absence of inducible ischemia in 102 of 115 cases (88.7%: k = 0.76, p < 0.00001). In studies in which the clinical and blinded interpretations were in agreement, there was greater ST-segment depression (STD) in echocardiographically positive compared with negative studies (mean STD 0.73 +/- 0.65 vs. 0.42 +/- 0.67 mm; p = 0.008). In contrast, studies in which there was disagreement had significantly less ST-segment changes (mean STD 0.19 +/- 0.56 mm; p = 0.012) despite comparable results on blinded wall motion analysis. Multiple logistic regression for factors related to the results of clinical and blinded wall motion analysis disclosed that angina pectoris and ST-segment changes were related to clinical interpretations, whereas only angina pectoris was related to the findings on blinded analysis. CONCLUSIONS: Clinical interpretations of echocardiographic images during DSE overall demonstrate good agreement with the results of blinded analysis. Ancillary testing data may influence the analysis of wall motion abnormalities, and thus the potential for observer bias exists unless these interpretations are performed blinded to other clinical data.

Echocardiographic evaluation of papillary fibroelastoma: a case report and review of the literature.

Papillary fibroelastomas comprise approximately 7.9% of benign primary cardiac tumors. Although papillary fibroelastomas were at first discovered incidentally at autopsy or during heart surgery, these tumors are increasingly being identified by echocardiography. This article reviews those papillary fibroelastomas detected by transthoracic or transesophageal echocardiography and discusses the echocardiographic features of these tumors, associated symptoms, and management. Echocardiography is important in influencing management decisions regarding excision, valve replacement, and valve repair.

Doppler evaluation of cardiac filling and ejection properties in humans during parabolic flight.

The cardiac filling and ejection properties of seven normal human subjects were examined during microgravity created on a National Aeronautics and Space Administration aircraft during parabolic flight. Doppler echocardiography was used to measure intracardiac velocities in sitting and supine subjects during three phases of flight: hypergravity (phase I), early microgravity (phase III), and late microgravity (phase IV). Heart rate declined 6% (P < 0.001) and right ventricular inflow velocities rose (46%, early; 26%, mean; P < 0.01) between phase I and phases III or IV in the sitting position only. Peak left ventricular outflow velocities rose 12% and inflow velocities rose (13%, early; 20%, mean) between phases I and IV while subjects were in the supine position (P < 0.05). A 14% rise in early velocities alone was seen between phases I and IV while subjects were in the sitting position (P < 0.05). In subjects entering microgravity while sitting, right heart chambers can accept additional venous return. When microgravity was entered while subjects were supine, however, venous augmentation was not observed. Left heart filling was more prominently enhanced when microgravity was entered while subjects were supine, suggesting a shift of fluid within the pulmonary vasculature.

Coronary artery fistula diagnosed by transesophageal echocardiography.

Coronary artery fistulas have been traditionally diagnosed by angiography. This report describes a congenital and a traumatic coronary artery fistula diagnosed by transesophageal echocardiography. Transesophageal echocardiography was superior to transthoracic echocardiography in both cases and to angiography in one case. Transesophageal echocardiography may now be the procedure of choice in diagnosing coronary fistula.

Central hemodynamics in a baboon model during microgravity induced by parabolic flight.

We developed a chronically instrumented nonhuman primate model (baboon) to evaluate the central cardiovascular responses to transient microgravity induced by parabolic flight. Instrumentation provided simultaneous recording of high fidelity (Ao) and pulmonary artery (PA) pressures, right and left ventricular and atrial pressures, Ao and PA blood flow velocities and vessel dimensions, ECG and pleural pressures. Four daily flights in 1991 and five in 1992 were flown with forty parabola per flight. Animals flown in 1991 were not controlled for volume status. Animals flown in 1992 were studied in one of three conditions: 1) volume depleted by furosemide (DH), 2) volume expanded by saline infusion (VE), and 3) euvolemic (EU, no intervention, used for echo only). Mean right atrial pressures (RAP) during 1991 flights had a variable early microgravity response: increases in n=3 and decrease in n=3 (supine) and increases in n=5, decreases in n=2 (upright). In 1992 flights, DH, upright and supine, changed -10 +/- 4.1 mmHg, -3.2 +/- 2.2 mmHg, respectively (p < .05) compared to the pull-up phase. In contrast, VE changed (from pull-up to microgravity) +13 +/- 1.5 mmHg and +4.25 +/- 2.9 mmHg (upright and supine, respectively, p < .05). EU increased with microgravity +6.9 +/- .9 mmHg (upright only). LAP responses were similar, but more variable. Finally, heart chamber areas paralleled pressure changes. Thus, right and left heart filling pressure changes with sudden entry into microgravity conditions were dependent on initial circulatory volume status and somewhat modified by position (supine vs upright).

The shortened advanced course for Army physicians.

The Army uses a series of career courses to prepare officers for progressive assignments. These courses have not been widely utilized by Army physicians. To improve the military education of physicians, an abbreviated Advanced Course was developed by the Academy of Health Science. A study of this course by the physicians attending its first offering showed that 8 weeks was an appropriate length. Information is provided to help improve the course and encourage attendance by Army physicians. This course will likely become mandatory and will be a key element in the training of all Army physicians.

Transesophageal echocardiographic evaluation of baboons during microgravity induced by parabolic flight.

The central cardiovascular responses to transient microgravity are not well understood. Theoretically, entrance into microgravity results in the loss of the hydrostatic pressure head and an increase in central venous pressure (CVP) as a consequence of augmented venous return. However, controversy exists regarding the time course and magnitude of cephalad blood volume shifts and its relationship to central atrial filling pressures. On the June 1991 STS 40 shuttle mission, pre-launch echocardiograms suggested changes in cardiac dimensions occurred while the astronauts were in the supine, feet-up position. Furthermore, a CVP line in an astronaut (n=1) demonstrated an unexpected abrupt decrease in CVP during orbital insertion. In April 1991, our laboratory performed Doppler echocardiography in 6 normal human volunteers during parabolic flight. Increases in right ventricular velocities reflecting a central shift of blood volume was demonstrated in subjects examined in the sitting position. However, test subjects examined in the horizontal positions had no significant rise in Doppler velocities. In addition, Latham et al noted variable central cardiovascular responses in chronically instrumented baboons during early microgravity. Transthoracic echocardiography (TTE) is a feasible method to noninvasively examine cardiac anatomy during parabolic flight. However, transducer placement on the chest wall is very difficult to maintain during transition to microgravity. In addition, TTE requires the use of low frequency transducers (2.5 MHz) which limits resolution. Transesophageal echocardiography (TEE) is an established imaging technique which obtains echocardiographic information from the esophagus. It is a safe procedure and provides higher quality images of cardiac structures than obtained with TTE. Since there are no interposed structures between the esophagus and the heart, higher frequency transducers can be used and resolution is enhanced. With TEE, a flexible transducer tip permits contact with the esophageal mucosa, allowing for consistent imaging. This study was designed to determine whether TEE was feasible to perform during parabolic flight and to determine whether acute central volume responses occur in acute transition to zero gravity (0G) by direct visualization of the cardiac chambers.

Circulatory filling pressures during transient microgravity induced by parabolic flight.

Theoretical concepts hold that blood in the gravity-dependent portion of the body would relocate to more cephalad compartments under microgravity conditions. The result is an increase in blood volume in the thoracic and cardiac chambers. This increase in central volume shift should result in an increase in central atrial filling pressures. However, experimental data has been somewhat contradictory and nonconclusive to date. Early investigations of peripheral venous pressure and estimates of central venous pressure (CVP) from these data did not show an increase in CVP in the microgravity condition. However, CVP recorded in human volunteers during the parabolic flight by Norsk revealed an increase in CVP during the microgravity state. On the June 1991 STS 40 shuttle mission, a payload specialist wore a fluid line that recorded CVP during the first few hours of orbital insertion. These data revealed decreased CVP. When this CVP catheter was tested during parabolic flight in four subjects, two subjects had increased CVP recordings and two other subjects had decreased CVP measurements. In April 1991, our laboratory performed parabolic flight studies in several chronic-instrumented baboon subjects. It was again noted that centrally recorded right atrial pressure varied with exposure to microgravity, some animals having an increase and others having a decrease. Thus, data presently available has demonstrated a variable response in the mechanism not clearly defined. In April 1992, we determined a test hypothesis relating the possible mechanism of these variable pressure responses to venous pressure-volume relationships.

Anomalous origin and course of coronary arteries in adults: identification and improved imaging utilizing transesophageal echocardiography.

Anomalous origin of a coronary artery is rare, but may represent a clinically significant abnormality, since some anomalies are associated with myocardial ischemia, infarction, and sudden death. Diagnosis may elude routine screening procedures, and even when an anomalous vessel is identified angiographically, it may be difficult to delineate its true course on the basis of angiography alone. The purpose of this study was to determine whether transesophageal echocardiography (TEE) is of value in making the diagnosis and outlining the course of anomalous coronary arteries. Five adult patients with anomalous origin of a coronary artery were studied by monoplane TEE and selective coronary angiography. Transthoracic echocardiography (TTE) was also performed in four of these five patients. Anomalous coronary ostia were visualized in four of five patients utilizing TEE, but in none of four patients by TTE. A proximal segment of the anomalous coronary vessel was identified in all five patients by TEE, and in only two of four patients by TTE. TEE images were consistently of superior diagnostic quality. TEE is a valuable tool for the echocardiographic identification of anomalous coronary arteries, and is superior to TTE in adult patients.