[Diabetic cardiomyopathy: clinical, hemodynamic and histopathologic as]ects. Case report]

[Influence of diabetes mellitus on the prognosis of non-ST-elevation acute coronary syndromes]

AIM OF STUDY

Analyze the influence of diabetes mellitus on the prognosis, at short and middle term of patients with non-ST-segment-elevation acute coronary syndrome.

PATIENTS AND METHOD

We conducted a retrospective review of 308 consecutive medical records of patients admitted to the care unit of our department with a non-ST-segment-elevation acute coronary syndrome. One hundred and fifty-six patients were diabetics (group 1) and 152 were not (group 2). We compared the demographic, clinical, angiographic and therapeutic characteristics of the two groups and we analyzed the prognosis of diabetic and non-diabetic patients at short term (30 days) and at middle term (average: 28 months; extreme: 12 months, 72 months).

RESULTS

The mean age was similar into both groups (60.8 years). Diabetic patients were more often women (42.1% vs 23.1%) and presented a higher prevalence of systemic hypertension, dyslipidemia and family history of coronary artery disease. Smoking was more frequent in group 2. The rates of coronary angiography, percutaneous transluminal coronary angioplasty, and coronary bypass surgery were similar in the two groups. At 30 days, diabetic patients were at increased risk for acute heart failure (19.1% vs 6.4%) and for major cardiac events (12.5% vs 6.4%). A pejorative prognosis was also observed at middle term among diabetic patients. They were at greater risk for readmissions for non-ST-segment-elevation acute coronary syndrome (42% vs 25%), for major cardiac events (49.3% vs 31.6%) and for new revascularizations (17.3% vs 7.2%). In a Cox multivariate analysis, diabetes mellitus remains an independent risk factor for major cardiac events at middle term.

CONCLUSION

Our study confirms the pejorative prognosis of acute coronary syndromes without ST elevation at short and middle term in diabetic patients.

Asymptomatic diabetic cardiomyopathy: a noninvasive study

Forty-nine diabetic patients (26 type I and 23 type II), free of cardiovascular disease symptoms, were compared with 32 controls in a noninvasive study of left ventricular (LV) function. Absence of ischemic cardiopathy was confirmed by routine investigations and an exercise electrocardiogram using 12 leads with a thallium-201 myocardial scintigraphy. Diabetic patients had (1) a significantly prolonged mean isovolumetric relaxation time (IVRT) assessed by M-mode echocardiography and phonomechanography; (2) a significantly reduced E-F slope; (3) an increased mean Weissler index (pre-ejection period/LV ejection time). The IVRT and E-F slope abnormalities reflect increased myocardial stiffness and impaired LV compliance. The increased Weissler index reflects impaired myocardial contractility. These abnormalities were not related to sex, age, duration of diabetes or to the presence or extent of complications. No significant difference was found between diabetic patients and controls for mean diastolic and systolic LV diameters, thickness of the posterior wall or of the interventricular septum, assessed by echocardiography, or for the ejection fraction, determined by radionuclide angiocardiography. Finally, more than half of the patients with a frankly abnormal IVRT, Weissler index and E-F slope had had diabetes for less than 5 years, some even less than 2 years, without complications. These data show: (1) evidence of LV dysfunction specific to diabetes and unrelated to ischemic cardiopathy and hypertension; (2) the possible involvement of a metabolic factor in this early asymptomatic LV abnormality rather than microangiopathy.

[Existence of asymptomatic changes in left ventricular function in the diabetic. Noninvasive study]

49 diabetics (D) (26 IDD and 23 NIDD) were compared to 32 controls (C). Absence of ischemic cardiopathy (IC) was confirmed by routine investigations and noninvasive cardiovascular techniques, including an exercise ECG using 12 leads and a thallium 201 scintigraphy. Our results show: a) a prolonged mean isovolumetric relaxation time (IVRT) as studied by the M mode echocardiography and phonomechanography: D = 0,10 sec +/- 0,04; C = 0,05 sec +/- 0,02; p less than 0,0001; b) a reduced mean EF slope: D = 97,48 +/- 37,08 mm / sec; C = 125,68 +/- 34,35; p less than 0,005; c) a high mean Weissler index (ratio of PEP to LVET): D = 40 +/- 0,08; C = 33 +/- 0,05; p less than 0,01. IVRT and EF slope abnormalities are related to increased myocardial stiffness and impaired LV compliance. In the absence of changes in preload and afterload, the high Weissler index reflects impaired contractility of the myocardium. These abnormalities are related neither to the duration of diabetes nor to the presence or severity of the complications. With the M mode echocardiography, mean diastolic and systolic thickness of the septum is greater in D with retinopathy than in C (p less than 0,005 and p less than 0,03 respectively); mean diastolic and systolic thickness of the posterior wall is greater in NIDD than in C (p less than 0,001 and p less than 0,025). We conclude that there is evidence of left ventricular functional abnormalities specific to diabetes and unrelated to IC and hypertension. Our findings support the hypothesis that they may be due to metabolic disorders and/or myocardial microangiopathy.