Troponin-T in unstable angina--a clinical and angiographic study.

OBJECTIVE: To examine the prognostic significance of Troponin-T in patients admitted with unstable angina and to study their angiographic morphology. DESIGN: Single centre, prospective study of in hospital events. SETTING: Intensive coronary care unit of a large municipal general hospital. SUBJECTS: 128 consecutive patients admitted with a diagnosis of unstable angina (Braunwald's classification). METHODS: Measurement of Troponin-T by qualitative assay at admission, coronary angiography between 5th to 7th day. MAIN OUTCOME MEASURES: In hospital adverse cardiac events--recurrent angina, new myocardial infarction or cardiac deaths. RESULTS: Fifty six (43.7%) patients had a positive test. The incidence of recurrent angina was significantly higher in the Trop-T positive group (57.1% vs 11.1%, p < 0.001). Six patients of this developed acute myocardial infarction subsequently whereas none of the patients in the Trop-T negative group developed acute MI (10.7% v/s 0%, p = 0.05). There were two deaths in the Trop-T positive group and none in the Trop-T negative group. 44 (78.5%) patients of the Trop-T positive group and 60 patients in the Trop-T negative group underwent coronary angiography. There was no significant difference in the incidence of single vessel disease (27.2% v/s 20%, p = NS) or multivessel disease (72.7% v/s 69.9%, p = ns). None of the patients with a positive Trop-T had normal coronary angiography whereas 6 patients in the Trop-T negative group had a normal coronary angiography (0% v/s 10%, p < 0.05). Patients with a positive troponin T test had a significantly higher incidence of type B lesions and a higher incidence of intracoronary thrombus. CONCLUSIONS: The in hospital outcome of Trop-T positive patients was significantly worse than patients with a negative test. Patients with a positive troponin T test had more complex coronary morphology and a higher incidence of intracoronary thrombus. We conclude that troponin-T can be used as a prognostic marker in patients with unstable angina.

Coronary stenting in diabetics: six months clinical and angiographic outcome.

The aim of this study was to assess the clinical and angiographic outcome of coronary stenting in diabetics as compared to non-diabetic patients. A total of 114 patients undergoing coronary angioplasty with stenting were prospectively evaluated. There were 30 diabetic (group A) and 84 non-diabetic (group B) patients. There were no significant differences in both the groups with respect to other risk factors and clinical characteristics. Both the groups were also comparable in terms of lesion morphology and stent types. The clinical endpoints were recurrent angina, reinfarction, cardiac death and need for target vessel revascularisation. The angiographic endpoint was angiographic restenosis at six months. There were 70 males and 44 female patients with a mean age of 55 +/- 12 years. Angiographic follow-up was completed in 85 (74.7%) patients which included 25 (83.3%) patients in group A and 60 (71.4%) in group B. Among clinical events at 30 days, the incidence of recurrent angina was 10.0 percent versus 8.3 percent (group A and B; p = NS) and incidence of reinfarction was 6.6 percent versus 5.9 percent (group A and B; p = NS), respectively. At six months, recurrent angina was seen in 16.6 percent versus 15.4 percent (p = NS) and reinfarction was seen in 10.0 percent versus 8.3 percent (p = NS) in group A and B, respectively. There were no deaths in either group. The angiographic restenosis rate was significantly higher in diabetics compared to non-diabetics (40.0% vs 23.3%; p = 0.02). The need for target vessel revascularisation was higher in diabetics as compared to non-diabetics (16.0% vs 6.6%; p = 0.03). We conclude that in spite of using coronary stents, the diabetics have higher restenosis rate and higher target vessel revascularisation rate than the non-diabetic patients.

Preconditioning the human myocardium with intracoronary adenosine.

This study was designed to study the role of adenosine in ischaemic preconditioning. The clinical, electrocardiographic and metabolic parameters of ischaemia were compared before and after intracoronary adenosine during percutaneous transluminal coronary angioplasty in 15 patients with significant stenosis of the left anterior descending artery. Baseline ischaemia was demonstrated by inflating the balloon of appropriate size at its nominal pressure for 30 seconds. Intracoronary adenosine was then administered in dose of 1000 to 6000 mgm/ml. The balloon was repositioned and inflated at nominal pressure for 180 seconds. As compared to 1st balloon inflation, the 2nd balloon inflation produced less severe chest pain, less ST segment deviation on the intracoronary ECG (7.40 +/- 3.94 vs 4.30 +/- 2.15 mm; p < 0.05) and lower coronary sinus lactate levels as compared to the first (0.28 +/- 0.06 vs 0.22 +/- 0.04 mmol/lit; p < 0.05). In conclusion, this study proves that by injecting intracoronary adenosine it is possible to precondition the human myocardium.

Adenosine-induced chest pain: is it due to myocardial ischaemia? Clinical, electrocardiographic, haemodynamic and metabolic study.

Adenosine has recently been demonstrated to be a mediator of angina in human beings. The present study was undertaken to document the presence or absence of myocardial ischaemia on clinical, haemodynamic, electrocardiographic and metabolic evidences after intracoronary administration of adenosine. Fifteen patients with chronic stable angina (12 males and 3 females), positive exercise stress test and documented significant stenosis of the left anterior descending coronary artery (LAD) were included in the study. The surface and intracoronary electrocardiograms (ECGs), pulmonary artery diastolic pressure and coronary sinus lactate levels were monitored at baseline and after intracoronary administration of adenosine in all patients. Adenosine was administered intracoronary in doses of 1000-8000 microgram depending on the provocation of chest pain. Typical angina was observed in all patients. There were no signs of ischaemia on surface or intracoronary ECG. There was no statistically significant difference between the pulmonary artery diastolic pressure and coronary sins lactate levels at baseline and post-adenosine administration (p > 0.05). It is concluded that intracoronary administration of adenosine produces chest pain in patients with chronic stable angina by mechanism other than myocardial ischaemia.

Coronary artery stenting in acute myocardial infarction.

Little information is available on the use of coronary stents to treat suboptimal results during direct angioplasty in acute myocardial infarction (AMI). In this study, we report 16 cases of AMI who underwent stent implantation in infarct-related artery for suboptimal results and their 6 months angiographic follow-up. Immediate angiographic success was achieved in all patients. The minimal luminal diameter increased from 0.06 +/- 0.12 mm to 2.89 +/- 0.12 mm (p < 0.001). One patient died in the hospital on day 8 due to subacute stent thrombosis. No patient required emergency bypass surgery. Two patients required blood transfusion for groin haematoma and one required intracoronary thrombolysis. All patients underwent exercise stress test at 1 month and at 3 months and coronary angiography at 4 months or earlier it indicated. At the end of 6 months follow-up, 4 patients had a positive exercise test and coronary angiography revealed angiographic restenosis in 3 and progression of disease in other vessels in 1 patient. We conclude that stent deployment is a viable option to treat suboptimal results after direct angioplasty in AMI.