Heart: first published as 10.1136/hrt. 2009.165969 on 28 May 2009. Downloaded from diabetic patients with and without TZD treatment who underwent surgical valve replacement for mitral stenosis (MS), and related them to the heart function. Nineteen non-TZD-treated and 13 TZD-treated (> 24 weeks of monotherapy in the previous year) type 2 diabetic patients who underwent mitral valve replacement (area (1.2 cm2) participated in the study. Patients with previous insulin treatment, heart failure, myocardial infarction, coronary stenosis. 70%, or other severe diseases were excluded (table 1). The percentage fractional shortening (FS)(Doppler echocardiography), within 30days before valve replacement, was calculated as:% FS=((LVDd2LVDs)/LVDd) 6100, where LVDd= left ventricular diastolic diameter and LVDs= left ventricular systolic diameter. Myectomy samples (10–20 mg) were removed from the LV septum during valve replacement surgery. Myocardial samples were stained with haematoxylin and eosin and oil red-O for evidence of intramyocyte lipid accumulation, and analysed by reverse transcriptase-PCR (RT-PCR) amplification western blot analysis for PPARc determinations (Santa Cruz Biotechnology, DBA, Milan, Italy). One-way analysis of variance for normally distributed data and the Kruskal–Wallis test for non-normally distributed data were used. Spearman correlation was used for non-parametric data. There were no significant differences in the MS area, glycaemia and HbA1c among the groups before surgery (table 1) and no differences for cardiovascular risk factors and concomitant treatments (data not shown). The mean (SD) duration of the TZD treatment was 9.5 (2.2) months. TZD-treated patients had a lower percentage of LV FS (p, 0.05) than non-TZD-treated patients. H&E staining of heart specimens from TZD-treated patients revealed vacuolated cells, consistent with intracellular accumulation of lipid (fig 1). Oil red-O staining showed numerous droplets of lipid in myocytes of TZD-treated patients (table a). There was a negative correlation between the percentage of both vacuolated myocytes and oil red-O staining positive myocytes and FS (R= 20.519, p, 0.001; R= 20.387, p, 0.01). Higher levels of both PPARc protein and mRNA as well as strong immunostaining for PPARc protein were seen in biopsy samples from the TZD-treated patients compared with non-TZD-treated patients (p, 0.01)(fig 1). The percentage of vacuolated myocytes, oil red-O staining positive myocytes and FS were significantly correlated with PPARc protein levels (R= 0.436, p, 0.01; R= 0.478, p, 0.01; R= 20.597, p, 0.001).