Temporal obesity trends in patients undergoing transthoracic echocardiography 2002-2006

Feasibility of SPECT myocardial perfusion imaging in the super-obese using a multi-head semiconductor camera with attenuation correction

BACKGROUND

Obesity is not only associated with an increased risk of coronary artery disease, but also decreases the accuracy of many diagnostic modalities pertinent to this disease. Advances in myocardial perfusion imaging (MPI) have mitigated somewhat the effects of obesity, although the feasibility of MPI in the super-obese (defined as a BMI > 50) is currently untested. We undertook this study to assess the practicality of MPI in the super-obese using a multi-headed solid-state gamma camera with attenuation correction.

METHODS

We retrospectively identified consecutive super-obese patients referred for MPI at our institution. The images were interpreted by 3 blinded, experienced readers and graded for quality and diagnosis, and subjectively evaluated the contribution of attenuation correction. Clinical follow-up was obtained from review of medical records.

RESULTS

72 consecutive super-obese patients were included. Their BMI ranged from 50 to 67 (55.7 ± 5.1). Stress image quality was considered good or excellent in 45 (63%), satisfactory in 24 (33%), poor in 3 (4%), and uninterpretable in 0 patients. Rest images were considered good or excellent in 34 (49%), satisfactory in 23 (33%), poor in 13 (19%), and uninterpretable in 0 patients. Attenuation correction changed the interpretation in 34 (47%) of studies.

CONCLUSIONS

MPI is feasible and provides acceptable image quality for super-obese patients, although it may be camera and protocol dependent.

Lack of reduction of left ventricular mass in treated hypertension: the strong heart study

Background

Hypertensive left ventricular mass (LVM) is expected to decrease during antihypertensive therapy, based on results of clinical trials.

Methods and Results

We assessed 4‐year change of echocardiographic LVM in 851 hypertensive free‐living participants of the Strong Heart Study (57% women, 81% treated). Variations of 5% or more of the initial systolic blood pressure (SBP) and LVM were categorized for analysis. At baseline, 23% of men and 36% of women exhibited LV hypertrophy (LVH, P<0.0001). At the follow‐up, 3% of men and 10% of women had regression of LVH (P<0.0001 between genders); 14% of men and 15% of women, free of baseline LVH, developed LVH. There was an increase in LVM over time, more in men than in women (P<0.001). Participants whose LVM did not decrease had similar baseline SBP and diastolic BP, but higher body mass index (BMI), waist/hip ratio, heart rate (all P<0.008), and urinary albumin/creatinine excretion (P<0.001) than those whose LVM decreased. After adjusting for field center, initial LVM index, target BP, and kinship degree, lack of decrease in LVM was predicted by higher baseline BMI and urinary albumin/creatinine excretion, independently of classes of antihypertensive medications, and significant effects of older age, male gender, and percentage increase in BP over time. Similar findings were obtained in the subpopulation (n=526) with normal BP at follow‐up.

Conclusions

In a free‐living population, higher BMI is associated with less reduction of hypertensive LVH; lack of reduction of LVM is independent of BP control and of types of antihypertensive treatment, but is associated with renal damage.

The impact of obesity on long-term survival after coronary artery bypass grafting

BACKGROUND

Obesity is a well-known risk factor for coronary artery disease. The objective of our study was to examine the impact of obesity on long-term survival after coronary artery bypass grafting (CABG).

MATERIALS AND METHODS

Using prospectively gathered data, we reviewed records of 1163 consecutive patients who underwent isolated primary CABG between 1997 and 2007. We compared outcomes of obese patients (body mass index [BMI] > or = 30 kg/m(2); n = 472) and non-obese patients (BMI < 30 kg/m(2); n = 691). Long-term survival was assessed by using Kaplan-Meier curves generated by log-rank tests and adjusted for confounding factors with Cox logistic regression analysis.

RESULTS

Obese patients were slightly younger (60 +/- 8 versus 63 +/- 9y; P < 0.0001), were less likely to be current tobacco smokers (30% versus 41%; P < 0.0001), had a higher incidence of diabetes (51% versus 33%; P < 0.0001), and had a lower incidence of cerebral vascular disease (18% versus 24%; P = 0.009) than non-obese patients. The two groups of patients had similar 30-d rates of mortality (1.3% versus 1.5%; P = 0.8) and major adverse cardiac events (2.3% versus 2.5%; P = 0.9). Adjusted Cox regression survival curves were also similar between the two groups of patients (adjusted hazard ratio, 1.2; 95% confidence interval, 0.8-1.8; P = 0.28).

CONCLUSIONS

Obese patients who underwent CABG had 30-d mortality rates and early outcomes similar to those of non-obese patients. Long-term survival was also similar between these two groups of patients after adjustment for confounding variables.