TAHAR EL KANDOUSSI, SARA ECHERKI, NAWAL DOGHMI, MOHAMED CHERTI. SEcurite de l’Echocardiographie de stress : plutôt l’effort. Cardiology B Department, Ibn Sina University Hospital, Rabat, Morocco

INTRODUCTION Stress echocardiography is an established clinical testing method for the detection of coronary artery disease. More sensitive marker for myocardial ischemia than electrocardiographic changes or chest pain alone. Exercise stress echocardiography should be the first choice in patients with suspected CAD. Safety and tolerability of the different stress modalities have been investigated in numerous studies. This is the first study conducted in Moroccan labs.

METHODS Population study We retrospectively studied 311 patients with known or suspected coronary artery disease, referred to our department ( Cardiology B Department, Ibn Sina University Hospitaf ) for a myocardial ischemia assessment between 2008 and underwent exercise stress echocardiography and 108 had dobutamine stress echocardiography Clinical characteristics were recorded for all patients.

Stress protocol Exercise stress Exercise stress :  Semi-supine bicycle ergometer, 25 W incremental loading every 2 minutes. Pharmacological stress (dobutamine). Pharmacological stress (dobutamine).  5 to 10 μ g/kg per min increased by 10 μ g/kg every 3 min up to a max of 40 μ g/kg per min.  Atropine was added at doses of 0.25 mg each min to a max of 2mg (from 20 μ g/kg per min dobu)

Echocardiographic analysis Ischemic response was defined as: Ischemic response was defined as:  New or worsening of pre-existing wall motion abnormalities in 2 contiguous segments.  Biphasic response experimented operator (N.D) Images analysis was made by the same experimented operator (N.D) Tests interruption Tests interruption : 85% of age-predicted target heart rate,severe chest pain, ST elevation, new segmental wall motion abnormalities or significant adverse effects.

Statistical analysis Continuous variables are expressed as means ± standard deviations and categorical variables are expressed as percentages. The statistical analysis was performed using SPSS version 18.0 p < 0.05 was considered statistically significant.

RESULTS DEMOGRAPHIC CHARACTERISTICS EXERCISEDOBUTAMINEP Number of patients Age (years) 59,262,90,001 Masculine gender (%) 78,944,40,0001 Demographic characteristics :

CARDIOVASCULAR RISK FACTORS EXERCISEDOBUTAMINEp Diabetes (%) 27,144,40,002 Hypertension (%) 38,459,30,001 Hypercholesterolemia (%) 3535,2NS Smoking (%) 47,826, Cardiovascular risk factors :

PMHExerciseDobutamineP Optimal medical treatment (%) 53,441,7NS Prior MI (%) 21,0711,110,029 Prior PCI (%) 53,720,40,0001 Prior CABG (%) 16,50,01 HF13,7911,11NS Past medical history

RESULTSEXERCISEDOBUTAMINEp Echocardiographic positivity (%) 23,1%13,2%0,003 Maximal Stress test (%) 81,37%88,34%NS Percentage of age predicted heart rate 90,51%92,89%NS Maximal heart rate 145,42 ±17,29 146,00± 18,17 NS - Maximal systolic BP ( mmHg) - Maximal diastolic BP ( mmHg) 190,25 ±29,03 91,37 ±16,18 170,73 ±35,67 80,50 ±16,58 0,00010,0001 Results of the stress tests in the study population

EXERCISEDOBUTAMINEP Major rhythmic events (%) 02,8NS Minor rhythmic events (%) 19,243,50,0001 Severe hypotension (%) 03,7NS Minor side effects (%) 3,413,90,001 Adverse events:

 Major events = 4 patients (in the dobutamine group): 1 MI 2 sustained supraventricular tachycardia 1 sustained ventricular tachycardia.  Minor rhythmic complcations : significant difference+++

Dobutamine+ atropine:  78,5% of dobutamine tests.  Mean dose = 0,66±0,55 mg.

DISCUSSION Both stress modalities are safedeath, MI, VF and high conduction disturbances were observed in 0.002%, 0.02%, 0.04% and 0.23% respectively with the use of dobutamine. Both stress modalities are safe: death, MI, VF and high conduction disturbances were observed in 0.002%, 0.02%, 0.04% and 0.23% respectively with the use of dobutamine.

MI (1 case) : MI (1 case) :  the reported incidence of MI is 0,02%.  Coronary artery spasm+++ Sustained ventricular tachycardia (1 case) Sustained ventricular tachycardia (1 case)  The reported incidence is 0.15%.  There is no relationship between this ventricular rhythm disturbance and inductile myocardial ischemia. -Mertes H et al: Symptoms, adverse effects, and complications associated with dobutamine stress echocardiography. Experience in 1118 patients. Circulation Katritsis DG et al : Sustained ventricular tachycardia induced by dobutamine stress echocardiography: A prospective study. Europace 2005 Supraventricular tachycardia ( 2 cases=1,8%) Supraventricular tachycardia ( 2 cases=1,8%)  Similar results were reported by Secknus et al. (1.7%), Pezzano et al. (1.6%) and Tsutsui et al. (1.6%)

Minor rhythmic complications Minor rhythmic complications: (p=0,0001)+++  Statistically higher incidence in the dobutamine group (p=0,0001)+++  Premature ventricular beats (31,48%) and NSVT(0,92%) the reported incidence is 33.7% and 2.1% respectively.  No difference in survival over the 3 years follow-up between the NSTV and the no NSTV groups in patients without inducible ischemia. -Cox DE et al : Prognostic significance of nonsustained ventricular tachycardia during dobutamine stress echocardiography. Am J Cardiol 2005

Severe hypotension: Severe hypotension:  O  Occurred in 3.7% of dobutamine tests, the reported incidence is 20%.  Associated to myocardial ischemia and poor cardiac prognostic.  Prognostic significance: hypotension during dobutamine infusion is an independent predictor of cardiac death and non-fatal myocardial infarction.

Atropine co administration in dobutamine stress echocardiography is safe+++ Atropine co administration in dobutamine stress echocardiography is safe+++  In our study, we used the early atropine protocol. Atropine administration was not associated to higher incidence of adverse events  The early injection of atropine during dobutamine stress echo has been demonstrated to reduce the duration and dose of dobutamine infusion, to reduce dobutamine related adverse events, while at the same time preserving a similar diagnostic accuracy.

CONCLUSION Stress modalities are safe but not equally safe, exercise tests are safer. The most common adverse events are the rhythmic disturbances and are usually minor and well tolerated.