Impact of ethnic variation and residential segregation on long-term survival following myocardial perfusion SPECT.

BACKGROUND: Ethnic characteristics of a neighborhood may impact upon all-cause mortality (ACM). It is not known whether this consideration remains a risk modifier among those being evaluated for CAD. METHODS: 6,477 pts (60 ± 13 years, male 38%) residing in NYC with normal or abnormal stress SPECT studies were assessed for ACM during a mean follow-up of 9 ± 3.8 years. Baseline CAD risk factors and ethnic characteristics of patient neighborhoods were considered. Zip-codes with >70% of one ethnicity was considered to be predominant of that ethnicity. RESULTS: There were 573 (20%) Hispanics (HS), 765 (27%) African-Americans (AA), and 250 (30%) Caucasians (CC) residing in areas >70% of their own ethnicity. Compared to CC, the risk for ACM was lower in HS (hazard ratio (HR) 0.68, 95% CI 0.57-0.8, P < .0001) and similar among AA (HR 1.1, 95% CI 0.95-1.41, P = .2). Among HS, there was a lower ACM among those residing in HS areas compared to those residing in a non-HS areas (HR 0.7 95% CI 0.56-0.9, P = .03) despite a lower median household income ($27,838 ± 3,328 vs $37,751 ± 17,036; P < .0001). This survival difference was not seen in CC and AA. CONCLUSION: Among patients referred for nuclear SPECT studies for suspected CAD, HS ethnicity was an independent predictor of a favorable prognosis. Among HS, the ethnic characteristic of patients' neighborhoods was an independent predictor of ACM. These results imply that ethnic social support is a potentially powerful modifier of patient outcomes among certain patient groups.

Synergistic effect of coronary artery disease risk factors on long-term survival in patients with normal exercise SPECT studies.

BACKGROUND: Normal exercise single-photon emission computed tomography (SPECT) studies are associated with a low event rate (<1.0%/year) during short-term follow-up. The influence of cardiac risk factors on long-term outcomes in such patients has not been well studied. MATERIAL AND METHODS: 2,597 patients (55 ± 12 years, male 41%) without a history of heart disease and a normal exercise SPECT between the years 1995 and 2006 were followed for a mean 6.8 ± 3.1 years for all-cause mortality assessed for using the Social Security Death Index. Baseline clinical risk factors and other clinical information were recorded for each patient and compared to outcomes. RESULTS: The mortality rate was 0.9%/year for our overall study population but varied according to individual baseline risk factors. Three coronary artery disease (CAD) risk factors were significant predictors of all-cause mortality: hypertension, diabetes, and smoking. When all three were absent, long-term all-cause mortality rate averaged 0.2%/year and when all three were present, all-cause mortality averaged 1.8%/year, constituting a 5.7-fold adjusted increase in risk (95% CI 2.7-12.8, P < .0001). CONCLUSIONS: During follow-up, annualized mortality rate varies markedly according to the number of CAD risk factors in patients without known heart disease and a normal exercise SPECT stress. Despite overall excellent long-term prognosis of a normal exercise SPECT, the burden of traditional CAD risk factors exert a strong synergistic influence on long-term survival and warrant aggressive treatment in this patient population.

Quantification of left ventricular remodeling in response to isolated aortic or mitral regurgitation.

BACKGROUND: The treatment of patients with aortic regurgitation (AR) or mitral regurgitation (MR) relies on the accurate assessment of the severity of the regurgitation as well as its effect on left ventricular (LV) size and function. Cardiovascular Magnetic Resonance (CMR) is an excellent tool for quantifying regurgitant volumes as well as LV size and function. The 2008 AHA/ACC management guidelines for the therapy of patients with AR or MR only describe LV size in terms of linear dimensions (i.e. end-diastolic and end-systolic dimension). LV volumes that correspond to these linear dimensions have not been published in the peer-reviewed literature. The purpose of this study is to determine the effect of regurgitant volume on LV volumes and chamber dimensions in patients with isolated AR or MR and preserved LV function. METHODS: Regurgitant volume, LV volume, mass, linear dimensions, and ejection fraction, were determined in 34 consecutive patients with isolated AR and 23 consecutive patients with MR and no other known cardiac disease. RESULTS: There is a strong, linear relationship between regurgitant volume and LV end-diastolic volume index (aortic regurgitation r2 = 0.8, mitral regurgitation r2 = 0.8). Bland-Altman analysis of regurgitant volume shows little interobserver variation (AR: 0.6 +/- 4 ml; MR 4 +/- 6 ml). The correlation is much poorer between regurgitant volume and commonly used clinical linear measures such as end-systolic dimension (mitral regurgitation r2 = 0.3, aortic regurgitation r2 = 0.5). For a given regurgitant volume, AR causes greater LV enlargement and hypertrophy than MR. CONCLUSION: CMR is an accurate and robust technique for quantifying regurgitant volume in patients with AR or MR. Ventricular volumes show a stronger correlation with regurgitant volume than linear dimensions, suggesting LV volumes better reflect ventricular remodeling in patients with isolated mitral or aortic regurgitation. Ventricular volumes that correspond to published recommended linear dimensions are determined to guide the timing of surgical intervention.

Impact of weight on long-term survival among patients without known coronary artery disease and a normal stress SPECT MPI.

BACKGROUND: While obesity has been shown to be associated with a worse mortality, an "obesity paradox"--lower mortality in obese patients--has been noted among many patients with coronary artery disease (CAD). The extent to which an obesity paradox operates among patients with only suspected CAD, is not well determined. METHODS AND RESULTS: A total of 3,673 patients (60 +/- 13 years, 36% males) with no history of heart disease and a normal stress SPECT were included in this study. Normal weight was defined as BMI of 18.5-24.9 kg x m(2); overweight 25-29.9 kg . m(2), obese >30 kg x m(2). The baseline clinical risk factors were recorded for each patient. The end point of the study was all-cause mortality. Of patients 942 (26%) were normal weight, 1,261 (34%) were overweight, and 1,470 (40%) were obese. Mean patient follow-up was 7.5 +/- 3 years. When compared to normal weight patients (event rate 3.2%/year), there was a lower incidence of death in the overweight (event rate 1.5%/year, P < .0001) and the obese (event rate 1.2%/year, P < .0001) groups. After controlling for baseline risk factors, using a reference HR = 1 for normal weight patients, there was a lower risk of death in the overweight (HR = .54, 95% CI .43-.7) and the obese groups (HR = .49, 95% CI .38-.63). CONCLUSION: In patients without known cardiac disease and a normal stress SPECT, overweight and obese patients had a lower rate of all-cause mortality compared to normal weight patients over long-term follow-up. This study substantially extends the spectrum of patients in whom the obesity paradox is present.