Elsevier

Journal of Nuclear Cardiology

Volume 19, Issue 6, December 2012, Pages 1182-1189
Journal of Nuclear Cardiology

Original Article
Abnormal glucose and lipid control in non-ischemic left ventricular dysfunction

https://doi.org/10.1007/s12350-012-9609-7Get rights and content

Abstract

Background

Cardiovascular risk factors are classically associated with coronary atherosclerosis. We sought to investigate whether risk factors are also associated with left ventricular (LV) dilatation, contractile impairment and reduced myocardial blood flow (MBF) in patients with non-ischemic LV dysfunction.

Methods

We studied 81 patients (59 males, age 60 ± 9 years) with mild-to-severe LV dysfunction (mean ejection fraction 37%, range 19%-50%), no history of diabetes and normal coronary arteries. Absolute MBF was measured by positron emission tomography and 13N-ammonia at rest and after dipyridamole (0.56 mg/kg I.V. over 4 min).

Results

Overt LV dysfunction (LV end-diastolic diameter >60 mm associated with LV ejection fraction <45%) was present in 42 patients (52%); severely depressed hyperemic MBF (<1.09 mL · min−1 · g−1) was present in 41 patients (51%). Using multivariate logistic regression analysis, low high-density lipoprotein cholesterol (HDL-C, P < .036), newly diagnosed non-insulin-dependent diabetes or insulin-resistance (NIDD/IR, P < .019) and the use of diuretics (P = .001) were independently associated with overt LV dysfunction. Low HDL-C (P = .015) and NIDD/IR (P = .048) were also independently associated with severely depressed hyperemic MBF.

Conclusions

Low HDL-C and NIDD/IR are associated with more severe LV impairment and reduced hyperemic MBF in non-ischemic LV dysfunction.

Introduction

The growing diffusion of cardiac positron emission tomography (PET) has provided new information on myocardial blood flow (MBF) regulation in different clinical conditions. Specifically, a reduced MBF at rest and during hyperemia has been increasingly correlated with factors affecting coronary function more than with the “traditional” effects of coronary stenoses.1,2 In subjects with normal coronary arteries and preserved left ventricular (LV) function, cardiovascular (CV) risk factors have been associated with depressed MBF and flow reserve.1,3 In patients with coronary artery disease (CAD), depressed global MBF has been correlated with global CV risk burden more than coronary anatomy.4 Finally, in patients with suspected CAD, a globally depressed MBF at rest and during stress has resulted the main independent predictor of adverse prognosis, overwhelming other common risk factors.5

The depression of global MBF at rest and during hyperemia has been also described by PET in patients with idiopathic LV dysfunction,6 carrying relevant prognostic information.7,8 Several factors have been proposed as possible determinants of altered myocardial perfusion in these patients, including the mechanical effects of myocardial contractile and hemodynamic impairment on coronary circulation, reduced capillary density, and primary microvascular dysfunction.1,9 Despite some evidence that traditional CV risk factors may occur frequently in this population10,11 and that coronary endothelial function may be impaired,12 the possible relationship between MBF abnormalities and CV risk factors has never been explored in these patients.

With these considerations in mind, we undertook this study to investigate whether CV risk factors, classically associated with CAD, are also predictors of a more severe LV dilatation and systolic impairment and of depressed MBF in patients with non-ischemic LV dysfunction.

Section snippets

Patients

We studied a group of 81 patients with different degrees of non-ischemic LV dysfunction, admitted to our Institute between 1999 and 2009. Inclusion criteria were between 20 and 80 years of age, LV ejection fraction ≤50% by two-dimensional echocardiography, normal coronary arteries or minimal luminal irregularities (<30% luminal diameter reduction) at angiography, and stable clinical conditions. Exclusion criteria were previous myocardial infarction, ≥moderate valvular heart disease, severe

Study Patients

The characteristics of patients as a whole or divided into two groups according to the presence of overt LV dilatation and systolic dysfunction are summarized in Table 1. The study population included mainly males, without overt heart failure (NYHA functional class I-II in 81% of cases) with prevalence of multiple CV risk factors. Patients with overt LV dilatation and dysfunction differed from the remaining patients because of a higher fasting plasma glucose and HOMA index, higher prevalence of

Discussion

This study shows that low HDL-C and NIDD/IR are associated with more severe LV dilatation and contractile impairment, and with more depressed MBF during stress in patients with non-ischemic LV dysfunction.

Acknowledgments

We thank Elisa Rizza and Stefano Masi for helping collecting the data. We also thank Silvia Pardini and Danilo Bonora for the production of 13N-Ammonia and Alison Frank for helping editing the manuscript. This study was partly supported by the Genocor FIRB 2005 project of the Italian Ministry of Education, University and Research (Grant N. RBLA05ACJZ).

Conflicts of interest

The authors have indicated that they have no financial conflicts of interest.

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