Relationship and prognostic value of coronary artery calcification by electron beam computed tomography to stress-induced ischemia by single photon emission computed tomography.

BACKGROUND: Stress single photon emission computed tomography (SPECT) is commonly performed in patients with abnormal electron beam computed tomography (EBCT) to define risk stratification, but the published prognostic data for patients undergoing both SPECT and EBCT are limited. The objective of the study was to examine the association and prognostic value between EBCT, coronary artery calcium score (CACS), and stress SPECT imaging. METHODS: We identified 835 patients (age 54.8 +/- 10.0 years, 77% male) who underwent EBCT and stress SPECT within a 3-month period. Coronary artery calcium score was categorized as normal (0), minimal (1-10), mild (11-100), moderate (101-400), and severe (>400). Single photon emission computed tomography summed stress score (SSS) was categorized as normal, low risk, intermediate risk, and high risk per Cedar Sinai criteria. Average follow-up was 4.8 +/- 3.2 years. End points were all-cause death, death/myocardial infarction (MI), and death/MI/late revascularization. RESULTS: The correlation of CACS to SSS was weak but statistically significant (r = +0.19, P < .001). The percentage of high-risk SSS increased with higher CACS scores; 4% of patients with normal EBCT and 18% with severe CACS had high-risk SSS. Coronary artery calcium score (chi2 = 11.4, P < .001), diabetes mellitus (chi2 = 4.6, P = .031), and chest pain class (chi2 = 8.7, P = .003) were independently associated with high-risk SPECT. The SSS (chi2 = 6.9, P = .009) and CACS (chi2 = 7.8, P = .005) were independently associated with mortality, as well as with both secondary end points of death/MI and death/MI/late revascularization. Only CACS predicted mortality in the 408 asymptomatic patients (chi2 = 5.2, P = .02), but these patients had an annual mortality of only 0.4% over the next 5 years. CONCLUSIONS: In selected patients undergoing both EBCT and SPECT, CACS is weakly correlated with SPECT SSS, likely reflecting the different information provided by EBCT and SPECT. Coronary artery calcium score is independently associated with high-risk SPECT after adjustment for clinical variables. Coronary artery calcium score and SSS are complementary for the prediction of mortality in symptomatic patients. Only CACS predicted mortality in the asymptomatic patients, but they had a low annual mortality.

Impact of pulmonary hypertension on the outcomes of noncardiac surgery: predictors of perioperative morbidity and mortality.

OBJECTIVES: We sought to determine the predictors of short-term morbidity and mortality (< 30 days) after noncardiac surgery in patients with pulmonary hypertension (PH). BACKGROUND: Pulmonary hypertension is considered to be a significant preoperative risk factor. METHODS: The PH and surgical data bases were matched from 1991 to 2003. Patients were excluded if PH was secondary to left heart disease, not present before surgery, or the procedure involved cardiopulmonary bypass. Univariate and multivariate logistic regression analyses were used to identify variables associated with short-term morbidity and mortality. RESULTS: Of 1,276 patients in the PH database, 145 patients (73% female) met all study criteria. The mean age (+/-SD) was 60.1 +/- 16.0 years. Right ventricular systolic pressure (RVSP) (mean +/- SD) on the two-dimensional echocardiogram was 68 +/- 21 mm Hg. There were 60 patients (42%) who experienced one or more short-term morbid event(s) (1.8 events/patient experiencing any event). A history of pulmonary embolism (p = 0.01), New York Heart Association functional class > or = II (p = 0.02), intermediate- to high-risk surgery (p = 0.04), and duration of anesthesia > 3 h (p = 0.04) were independent predictors of short-term morbidity. There were 10 early deaths (7%). A history of pulmonary embolism (p = 0.04), right-axis deviation (p = 0.02), right ventricular (RV) hypertrophy (p = 0.04), RV index of myocardial performance > or = 0.75 (p = 0.03), RVSP/systolic blood pressure > or = 0.66 (p = 0.01), intraoperative use of vasopressors (p < 0.01), and anesthesia when nitrous oxide was not used (p < 0.01) were each associated with postoperative mortality. CONCLUSIONS: In patients with PH undergoing noncardiac surgery with general anesthesia, specific clinical, diagnostic, and intraoperative factors may predict worse outcomes.

Differences in left ventricular ejection fraction and volumes measured at rest and poststress by gated sestamibi SPECT.

BACKGROUND: Some studies suggested that the poststress left ventricle ejection fraction (LV EF) is lower than rest LV EF in patients with stress-induced ischemia. METHODS AND RESULTS: By using a 2-day protocol and 30 mCi Tc-99m sestamibi, LV EF, end-systolic volume (ESV), and end-diastolic volume (EDV) were measured with gated SPECT. Of 99 eligible patients, 91 had technically adequate studies. Poststress LV EF minus rest LV EF was defined as DeltaLV EF. DeltaEDV and DeltaESV were similarly defined. Rest and poststress LV EF (r = 0.89), EDV (r = 0.78), and ESV (r = 0.93) were highly correlated (P <.001). Rest LV EF, EDV, and ESV were not significantly different between patients with and without stress-induced ischemia. DeltaLV EF was significantly lower in patients with stress-induced ischemia (-3.5% +/- 4.5% vs -1.1% +/- 4.7%, P = .02). Mean LV EF poststress in ischemic patients was 55.0% +/- 10.5% vs 61.2% +/- 10.0% in nonischemic patients (P = .008). However, only 1 patient (3%) with ischemia had DeltaLV EF that exceeded the 95% confidence limit of DeltaLV EF for normal patients. Ischemia was significantly associated with increased DeltaEDV and DeltaESV (P < .01). CONCLUSIONS: Stress-induced ischemia is associated with poststress reduction in LV EF and increased poststress EDV and ESV. However, the effect of ischemia on the difference between poststress and rest EF measurements is modest and rarely exceeds the confidence limits in normal patients undergoing 2-day protocols. In most patients, poststress LV EF is an accurate reflection of rest LV EF.

A curricular initiative for internal medicine residents to enhance proficiency in internal jugular central venous line placement.

OBJECTIVE: To determine the feasibility, efficacy, and outcomes of teaching Internal Jugular (IJ) central venous line placement (CVLP) to internal medicine residents in a hands-on training experience with adult patients. SUBJECTS AND METHODS: Data were obtained from 47 residents during their 3-year residency program through questionnaires and a proprietary system that tracks resident procedures. Twenty-five postgraduate year (PGY) 2 residents at the Mayo Clinic in Rochester, Minn, were assigned to IJ-CVLP training in the cardiac catheterization laboratory from January 2001 to June 2001. Their experience, analyzed immediately after training and at completion of residency, was compared with that of 22 PGY-2 residents in the same class who were not assigned to IJ-CVLP training. RESULTS: The median Likert scores of the residents' self-reported perception of independence in IJ-CVLP increased from 3.0 (mean +/- SD score, 2.8+/-1.4) before the intervention to 5.0 (4.4+/-0.9) after the intervention (P<.001, signed rank test). At graduation, trained residents had performed more IJ-CVLPs than the control residents (mean +/- SD, 17.8+/-8.4 vs 9.8+/-6.3, respectively; P<.001). Residents who received IJ-CVLP training, compared with those who did not, showed a significant increase in the mean percentage of IJ-CVLPs performed independently between PGY-1 (2.2%) and PGY-3 (31.2%) (P=.008). CONCLUSIONS: Training internal medicine residents to perform IJ-CVLP is feasible in the cardiac catheterization laboratory with supervision from an attending cardiologist. Trained residents performed significantly more IJ-CVLPs independently during their third year compared with their first year of training. We believe this initiative may be implemented successfully in graduate medical education curriculums.

Effect of exercise treadmill testing and stress imaging on the triage of patients with chest pain: CHEER substudy.

OBJECTIVE: To determine whether stress imaging for patients who are unsuitable for exercise treadmill testing (ETT) as part of a chest pain unit (CPU) triage strategy resulted in incremental benefit in clinical outcomes and relative costs compared with patients randomized to routine hospital admission. PATIENTS AND METHODS: Clinical outcomes and medical resource utilization were examined at the Mayo Clinic in Rochester, Minn, for 212 intermediate-risk patients with unstable angina randomized to a CPU and compared with 212 patients randomized to routine admission from November 21, 1995, to March 18, 1997. Patients in stable condition in the CPU underwent ETT; if patients were unsuitable for ETT, stress imaging was performed. Costs for CPU evaluation and outcomes were assessed during a 6-month follow-up. RESULTS: During the observation period, 60 patients (28%) were admitted to the hospital. Of the 152 remaining patients, 125 (82%) underwent ETT (91 had normal results), and 27 (18%) underwent stress imaging (3 had normal results). Patients with normal ETT or stress imaging results had no primary events at 6-month follow-up. Patients admitted to the hospital who underwent stress imaging had an insignificantly higher 6-month event rate compared with patients who underwent ETT (16.7% vs 8.1%; P=.38). The standardized resource-based relative-value units (RBRVUs) for patients who underwent ETT and stress imaging during follow-up were 19.4 and 56.4 RBRVUs, respectively, compared with 51.4 (ETT) and 52.1 (stress imaging) RBRVUs for similar numbers of patients randomized to routine admission. CONCLUSIONS: Exercise treadmill testing safely stratified most intermediate-risk patients with unstable angina and was less costly than routine admission. Patients not suitable for ETT are likely to have abnormal stress imaging results. They represent a higher-risk cohort that could be routinely admitted to the hospital without reducing the effectiveness of the CPU strategy.

A real-time computer model to assess resident work-hours scenarios.

OBJECTIVE: To accurately model residents' work hours and assess options to forthrightly meet Residency Review Committee-Internal Medicine (RRC-IM) requirements. DESCRIPTION: The requirements limiting residents' work hours are clearly defined by the Accreditation Council for Graduate Medical Education (ACGME) and the RRC-IM: "When averaged over any four-week rotation or assignment, residents must not spend more than 80 hours per week in patient care duties."(1) The call for the profession to realistically address work-hours violations is of paramount importance.(2) Unfortunately, work hours are hard to calculate. We developed an electronic model of residents' work-hours scenarios using Microsoft Excel 97. This model allows the input of multiple parameters (i.e., call frequency, call position, days off, short-call, weeks per rotation, outpatient weeks, clinic day of the week, additional time due to clinic) and start and stop times for post-call, non-call, short-call, and weekend days. For each resident on a rotation, the model graphically demonstrates call schedules, plots clinic days, and portrays all possible and preferred days off. We tested the model for accuracy in several scenarios. For example, the model predicted average work hours of 85.1 hours per week for fourth-night-call rotations. This was compared with logs of actual work hours of 84.6 hours per week. Model accuracy for this scenario was 99.4% (95% CI 96.2%-100%). The model prospectively predicted work hours of 89.9 hours/week in the cardiac intensive care unit (CCU). Subsequent surveys found mean CCU work hours of 88, 1 hours per week. Model accuracy for this scenario was 98% (95% CI 93.2-100%). Thus validated, we then used the model to test proposed scenarios for complying with RRC-IM limits. The flexibility of the model allowed demonstration of the full range of work-hours scenarios in every rotation of our 36-month program. Demonstrations of status-quo work-hours scenarios were presented to faculty as well as real-time demonstrations of the feasibility, or unfeasibility, of their proposed solutions. The model clearly demonstrated that non-call (i.e., short-call) admissions without concomitant decreases in overnight call frequency resulted in substantial increases in total work hours. Attempts to "get the resident out" an hour or two earlier each day had negligible effects on total hours and were unrealistic paper solutions. For fourth-night-call rotations, the addition of a "golden weekend" (i.e., a fifth day off per month) was found to significantly reduce work hours. The electronic model allowed the development of creative schedules for previously third-night-call rotations that limit resident work hours without decreasing continuity of care by scheduling overnight call every sixth night alternating with sixth-night-short-call rotations. DISCUSSION: Our electronic model is sufficiently robust to accurately estimate work hours on multiple and varied rotations. This model clearly demonstrates that it is very difficult to meet the RRC-IM work-hours limitations under standard fourth-night-call schedules with only four days off per month. We are successfully using our model to test proposed alternative scenarios, to overcome faculty misconceptions about resident work-hours "solutions," and to make changes to our call schedules that both are realistic for residents to accomplish and truly diminish total resident work hours toward the requirements of the RRC-IM.

Relationship between coronary artery calcification detected by electron-beam computed tomography and abnormal stress echocardiography: association and prognostic implications.

OBJECTIVES: The purpose of this study was to compare the results and prognostic value of electron-beam computed tomography (EBCT) and exercise echocardiography. BACKGROUND: Although patients with elevated coronary artery calcium scores (CACS) might be referred for exercise echocardiography, the association of EBCT CACS with wall motion score index (WMSI) is not known. METHODS: Patients without known coronary artery disease who underwent both clinically indicated EBCT and exercise echocardiography within a 3-month period were identified. Exercise WMSI was based on a 16-segment model (normal = 1; abnormal >1). The EBCT CACS was derived with the Agatston scoring system. Follow-up was obtained for the combined end point of death and myocardial infarction. RESULTS: The study population included 556 patients (age 54 +/- 10 years; 65% male). Correlation between EBCT CACS and exercise WMSI was limited (r = 0.17, p < 0.0001) but statistically significant. The proportion of patients with abnormal exercise WMSI increased with increasing CACS severity (chi-square = 19.1, p < 0.001). However, even in those with CACS >400, 66% had normal exercise WMSI. Age, CACS, and chest pain were independently associated with abnormal exercise WMSI. Events occurred in 12 (2%) patients. Wall motion score index (risk ratio [RR] 3.7, p = 0.023) and age (RR 1.9, p = 0.019) were associated with events. CONCLUSIONS: Electron-beam computed tomography CACS was predictive of abnormal exercise WMSI, but the majority of patients with elevated CACS had normal WMSI. Wall motion score index and age were the best predictors of events. Prospective studies are indicated to establish the relative roles of these tests in risk stratification.

Safety of expedited anticoagulation in patients undergoing transesophageal echocardiographic-guided cardioversion.

BACKGROUND: In patients undergoing transesophageal echocardiography-guided cardioversion, we evaluated the use and safety of an expedited in-hospital anticoagulation regimen that incorporates shorter-than-standard durations of precardioversion intravenous unfractionated heparin and postcardioversion bridging therapy with a low-molecular-weight heparin. METHODS: Adult patients who underwent successful transesophageal echocardiography-guided cardioversion for atrial fibrillation or atrial flutter between May 2000 and August 2003 were classified into 2 groups by duration of intravenous unfractionated heparin therapy (<24 h or > or =24 h) before transesophageal echocardiography and cardioversion. Safety end points evaluated included all-cause death, stroke or other thromboembolic events, and major bleeding complications within 1 month after successful cardioversion. RESULTS: The study population of 386 patients included 199 (52%) who received expedited intravenous unfractionated heparin (<24 h; minimum duration, <4 h) and 193 patients (50%) who were discharged on low-molecular-weight heparin therapy. The adverse event rates at 1-month follow-up were not significantly different between the 2 unfractionated heparin patient groups, and the rate of stroke among patients dismissed on low-molecular-weight heparin was less than 1%. No adverse events occurred among patients who received intravenous unfractionated heparin for less than 12 hours and who were dismissed on low-molecular-weight heparin bridging therapy. CONCLUSIONS: The use of an expedited heparin anticoagulation regimen in patients with atrial fibrillation or atrial flutter undergoing transesophageal echocardiography-guided cardioversion appears to be safe. Cardioversion can be performed as early as a few hours after initiation of intravenous unfractionated heparin, and bridging therapy with a low-molecular-weight heparin can be used after cardioversion until the international normalized ratio is therapeutic.

Apical ballooning syndrome in a postoperative patient with normal microvascular perfusion by myocardial contrast echocardiography.

Apical ballooning syndrome is classically described as transient left ventricular (LV) dysfunction, marked LV akinesia, and normal or near-normal coronary arteries. The etiology is unclear and there is limited information based on case reports and small case series. We describe a 35-year-old woman who underwent surgical hepatectomy and developed apical ballooning syndrome in the postoperative period. The novel use of myocardial contrast echocardiography (MCE) in this setting demonstrated intact microvascular perfusion and lack of coronary flow-limiting abnormalities despite apical akinesis. In select patients with similar clinical presentations, performing MCE is safe and may be pursued as an alternative to invasive coronary angiography.

Diagnosis and Treatment of Isolated Systolic Hypertension in the Elderly: Results of a Survey Four Years Post-SHEP.

There is limited data evaluating the impact on clinical practice of the 1991 SHEP study. To assess present approaches and attitudes to ISH, we surveyed 135 physicians during the spring of 1995. A questionnaire was designed to assess the physician's definition of ISH, views on clinical importance and etiology of ISH, choice of pharmacological intervention (if any), and opinions regarding SHEP's influence on current approaches to the management of ISH. Surveys were distributed to physicians at the weekly Internal Medicine and Cardiology Grand Rounds at The Mt. Sinai Medical Center, New York, NY from February through April 1995. Data were analyzed via Lotus 1-2-3 spreadsheet (Release 3.1 Que Corp.) and responses to opinion statements were factor analyzed on Systat Version 5.0 software. The response rate was 63.7% (87 physician responses). Nearly 50% of the respondents had read the SHEP article and 82.6% had "heard of the study." Approximately 60% believed ISH should be defined in accordance with the SHEP guideline (SBP is greater than 160 mm Hg and DBP is less than 90 mm Hg). Thirty percent of physicians would initiate pharmacological treatment at a SBP less than or equal to 155 mm Hg for patients aged 65-74 years. Of the 85% of physicians (n equals 73) who opted to medicate, the patient's age strongly determined the SBP at which pharmacological treatment would be initiated. Whereas 66% of physicians would use drug therapy for patients aged 65-74 with a SBP less than or equal to 160 mm Hg, 54% and 45% of physicians would consider the same for patients aged 75-84 and 85+, respectively. Thirty eight percent of physicians chose thiazide diuretics as sole first-line therapy. CCB and ACE inhibitors were chosen by 26.8% and 19.7% of physicians, respectively. When compared to younger physicians (less than 60 yrs), older clinicians ( at or above 60 yrs) were more likely to agree that the detection of ISH was not important and that treatment of ISH is ineffective. Survey results demonstrate a definite consensus for initiation of pharmacological treatment in elderly patients with ISH. Of note, a significant percentage of physicians would initiate therapy at SBP less than or equal to 155 mm Hg. This is a level of pressure for which no epidemiological data exists to support treatment. With respect to specific pharmacological treatment of ISH, a clear consensus is still lacking. The increased use of ACE inhibitors and CCB compared with previous studies may have significant impact on the future of treatment costs for the elderly.

Iron and peripheral arterial disease: revisiting the iron hypothesis in a different light.

The relationship between iron status and atherosclerosis has long been a topic of debate in the literature. Despite more than 25 years of research, there is no consensus regarding a causal relationship. To date, the vast majority of studies have focused on iron burden with respect to a hypothesized role in the onset and progression of coronary artery disease. However, the effect of iron in the coronary arterial system may differ mechanistically and therefore clinically from its effect in the peripheral arterial system. This review will summarize the biochemical, pathologic, animal, and clinical research data with respect to iron and atherosclerosis. This background will be expanded upon to provide insights into ongoing studies and paths for future investigations into the role of iron and peripheral arterial disease.

Endocardial flap of left atrial dissection following radiofrequency ablation.

This report describes an unusual mobile strand found by transesophageal echocardiography prior to a patient's second radiofrequency ablation for paroxysmal atrial fibrillation. This structure arose from the limbus of the left upper pulmonary vein, a location where radiofrequency energy bursts were delivered during the first ablation procedure. After seven months of therapeutic anticoagulation, there was no evidence of change in the size of the mass or of thromboembolism and the patient underwent radiofrequency ablation without complication. We believe this structure most likely represents an endocardial flap of left atrial dissection temporally related to radiofrequency ablation.