Unstable angina and non Q-wave myocardial infarction. Early risk stratification: Role of silent ischemia and coronary morphology

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The noninvasive identification of patients with angina and normal coronary arteries [Riconoscimento non invasivo dei pazienti con angina a coronarie normali.]

BACKGROUND. Although patients with syndrome X (angina and normal coronary arteries, in absence of coronary spasm, cardiomyopathy or valvulopathy) and those with stable angina as well as documented coronary artery disease share a similar clinical presentation (effort related symptoms, positive exercise stress testing and reversible perfusion defects), their prognosis is markedly different. Coronary atherosclerosis is usually progressive relative to morbidity and mortality. Conversely prognosis both in terms of persistence of pain and mortality appears to be benign in syndrome X. Most cardiologists favor proceeding with coronary angiography in all patients presenting with exercise induced ST depression and reversible perfusion defects. However, it should not be assumed that this strategy will remain the preferred one. The aim of this study was to assess whether non invasive testing could identify underlying coronary artery anatomy, thus prognosis in the above subset of patients. The approach was selected on a clearly stated objective of how isosorbide dinitrate and verapamil may influence coronary flow reserve, thus exercise stress testing in syndrome X. Nitrates have been shown to reduce coronary flow reserve during stress tachycardia. The opposite occurs with calcium blockers. METHODS. We studied 48 patients with effort angina referred to our laboratory for diagnostic evaluation. All patients underwent two separate sessions at one-day interval. Each session consisted of exercise stress testing before and after isosorbide dinitrate (s.l.; 5-10 mg) or verapamil (i.v.; 10 mg), given in a randomized crossover fashion. Angiography was performed within 3 months from testing. Efficacy of drugs in terms of exercise capacity was assessed by using the following criteria: 1) prevention of significant (> or = 0.1 mV) ST depression while reaching same workload levels attained during baseline testing; 2) improvement in the ischemic thresholds, that is an increase in: time to 0.1 mV ST depression > or = 120 sec., with heart rate (> or = 10 bpm) and rate pressure product (> or = 2 U x 1000) greater than those attained during baseline testing; 3) increase in time to peak exercise (> or = 120 sec). RESULTS. In syndrome X, both drugs resulted ineffective in one patient, one patient showed a favourable response to isosorbide dinitrate whereas the remaining 13/15 patients improved exercise capacity following verapamil, but not isosorbide dinitrate. The opposite occurred in coronary artery disease patients: both isosorbide dinitrate and verapamil were effective in 21/33 patients, and ineffective in 8/33 patients. The remaining 4 patients responded to isosorbide dinitrate but not to verapamil. CONCLUSIONS. 1) Verapamil, but not isosorbide dinitrate, improves exercise capacity in syndrome X; 2) this does not apply to patients with stable angina; 3) a favourable response to verapamil but not to isosorbide dinitrate is both a sensitive (86%) and specific (100%) method for identifying patients with angina and normal coronary arteries; 4) non invasive testing may select those effort angina patients who have to proceed directly to coronary angiography; 5) some patients with effort related angina may not require further investigation

Myocardial infarct with normal coronary vessels: an association with dysfunction of the coronary microcirculation

The association of acute myocardial infarction (AMI) with normal coronary arteries was analyzed prospectively. A series of 128 consecutive patients underwent coronary angiography within 1 week from AMI. Seven patients, all females, had no coronary artery lesions and were considered eligible for the study. All 7 patients underwent atrial pacing (10 g/min increments every 2 min), ergonovine testing (E; total dose 0.650 mg i.v.). Great cardiac vein flow (GCVF; thermodilution technique), mean aortic pressure (MAP), anterior coronary resistance (ACR) and myocardial lactate extraction [(Lac art-Lac gcv)/Lac art] were measured at baseline and during testing. Pacing-induced typical chest pain occurred in 5 patients: 4 of them showed concurrent significant (> or = 0.15 mV) ST downsloping. At peak pacing, GCVF increased only by < 50%, or even decreased, in all patients. Baseline lactate extraction (0.13 +/- 0.11) changed to lactate production (-0.15 +/- 0.10) in 7/7 patients. None of the patients showed focal epicardial coronary artery spasm following E. During testing, however, all 7 patients showed decrease in GCVF (110 +/- 47 versus 74 +/- 21; p < 0.005), increase in ACR (0.92 +/- 0.29 versus 1.43 +/- 0.20; p < 0.001), and significant coronary lactate production (-0.18 +/- 0.12). Six patients referred slight to moderate chest pain, which was accompanied by ST downsloping in 4.(ABSTRACT TRUNCATED AT 250 WORDS

Mitral anular plane excursion predicts coronary stenosis during stress echocardiography with dipyridamole

Abstract Funding Acknowledgements Type of funding sources: None. Background Dipyridamole stress echocardiography (DSE) is an important tool for detecting reversible ischemia in patients with suspected coronary artery disease (CAD); nonetheless, the results of the test are related to wall motion abnormalities, moderately operator-dependent, and left anterior descending (LAD) artery reserve, resulting in a moderate sensibility and specificity.  Purpose Aim Of our study was to evaluate whether an easy-to-use parameter like mitral annular plane systolic excursion (MAPSE) could be useful to identify CAD during DSE.  Methods We prospectively enrolled 512 patients that underwent DSE for suspected CAD; rest and peak MAPSE was acquired; 148 patients were referred to perform coronary angiography, with evidence of severe coronary stenosis in 91 patients.   The mean age was 66.7 ±11 years, male gender was prevalent (64%).  MAPSE at the peak was significantly different between patients with CAD and patient without (13,4mm vs 16,81 mm , p &amp;lt; 0.001); in fact, patients with CAD showed a blunted or no increase of MAPSE after dipyridamole infusion, with a significative difference in Delta Mapse (Mapse peak-Mapse rest) between groups ( -0.5mm vs 2.8mm) By using a Receiver Operating Curve, the Area under the curve was 0,764 (0.682-0.846), with the best cut-off value of +0.5mm (Sensibility 77%, Specificity 62% - Figure 1), comparabale with traditional methods like LAD reserve, FE reduction or Wall Motion Score Index.  Discussion to our knowledge, this is the first study that compared the behavior of MAPSE during dipyridamole infusion in patients with and without coronary artery disease. MAPSE is a well-known surrogate of longitudinal systolic function and has increased sensitivity over traditional methods of systolic performance such as LV-EF: in this context, dipyridamole induced reversible ischemia could affect prematurely MAPSE then EF or wall motion abnormalities. In our study, in patients with evidence of reversible ischemia during DSE, a blunted or no increase of MAPSE was able to predict CAD. Incorporating this easy-to-use parameter could improve the specificity of DSE and strengthen the suspect of reversible ischemia when clear wall motion abnormalities are not found. Abstract Figure. Mean value of Mapse and ROC curve </jats:sec