Nurse practitioners: a safe and competent choice for stress testing in myocardial perfusion scintigraphy

Transcription

1 Nurse practitioners: a safe and competent choice for stress testing in myocardial perfusion scintigraphy K Standbridge, E Reyes, K Latus, SR Underwood, J Riley Imperial College London & Royal Brompton Hospital, UK No conflict of interest

2 What is myocardial perfusion scintigraphy? MPS is a non-invasive investigation that provides effective and cost effective information in patients with known or suspected CAD It provides information on myocardial viability, function and ischaemia It involves injection of a radiopharmaceutical tracer during cardiovascular stress and again later at rest Stress image Rest image

3 Multi-professional issues Cardiovascular stress testing has traditionally been supervised by doctors There is a trend to hand the responsibility to nurses We perform ~4000 MPS per year, mainly nurse led Nurses work autonomously but a doctor is on site

4 Previous Studies Reyes et al (2002) demonstrated equal safety of doctor and nurse led stress Latus et al (2004) showed that nurses were better able to exclude than diagnose myocardial ischaemia from the clinical history An increase in nurse led stress in a wider and higher risk population requires that safety is confirmed in a larger study 1 Reyes EM, et al. Nuclear Medicine Communications 2002; 23: Latus KA. MSc Dissertation 2004, Imperial College London

5 Safety of non medical stress tests Stressor Nurse 1 n = Nurse 2 n = 108 Nurse 3 n = 467 Radiographer 4 n = 1197 Technologist 5 n = 156 MI or *serious arrhythmias 13 (0.075%) Death Medical supervision 0 1 (child) Not recorded 43 (3.5%) 3 (1.9%) 1. Stuart RJ, Ellestad MH. Chest 1980; 77: Annual audit of cardiac stress testing during MPS RBHNFT November Cerqueria MD, Verani MS, et al. JACC 1994; 23: Lette J, Tatum Jl, Fraser S, et al. J Nucl Cardiol 1995; 2: Dakik HA, Vempathy H, Verani MS, et al. J Nucl Cardiology 1996; 3: 410-4

6 Stress testing for MPS Dynamic exercise Pharmacological stress - Adenosine - Dipyridamole - Dobutamine Patient permission provided

7 Skills for cardiac stress Pharmacological stress can be performed only by someone with the appropriate knowledge and skills Cardiac physiology Pharmacology Indications Contraindications Stress protocols Treatment of complications Cardiopulmonary resuscitation Treatment of arrhythmias Radiation knowledge

8 Purpose To document the safety of cardiac stress testing during myocardial perfusion scintigraphy Methods A total of 525 consecutive patients were included in the study (April- March 2009) All patients attending for a clinically indicated MPS were included Routine stress and imaging protocols were used

9 Data Collection Adverse events defined as a clinical event caused by stress, either during or soon after mild, moderate, severe and serious Risk assessment determined by the EANM/ESC procedural guidelines for MPS Relationship between the chest pain history and the presence of inducible ischaemia Relationship between the stressor s assessment during stress and the presence of inducible ischaemia

10 Baseline characteristics, n = 525 Age mean ± SD (range) 65.3 ±11.9 (30-96) Weight, mean ±SD (range) Male Female 82kg ±18 (42-180) 306 (58%) 219 (42%) Known CAD 263 (50%) Nurse stressor Doctor stressor 366 (70%) 159 (30%) Adenosine Dobutamine 503 (96%) 22 (4%)

11 Frequency of adverse events 103 (20%) adverse events were reported There were no serious adverse events (death, MI, CHF, or hospital admission 6% 5% n =26 4% n =19 3% 2% n =12 n =10 n =12 1% 0% n =1 n =4 n =7 n =0 Vasovagal Hypertension Severe CP and ECG ECG Tachy- Severe Heart Block Broncho- SOB changes arrhythmias bradycardia spasm alone

12 Severity of adverse events 55% of adverse events were mild 100% Mild Moderate Severe 90% 8 patients had severe adverse events. All 8 studies were terminated early but completed successfully 80% 70% 60% 50% 40% 6 of the 8 severe events occurred with dobutamine and 2 with adenosine. 30% 20% 10% 0% All 8 patients made a full recovery and did not require further treatment

13 Safety 52 (10%) patients were high risk for cardiac stress testing High risk included recent cardiac arrest, myocardial infarction or unstable angina severe LV dysfunction left main stem disease (<50%) 35 of 52 (65%) were stressed by nurses

14 Predicting Ischaemia The stressors diagnosis of angina predicted the presence of ischaemia odds ratio 1.4, 95% CI 1.04 to 2.06, P = The stressors assessment of myocardial ischaemia from symptoms and ECG during stress predicted the presence of ischaemia odds ratio 2.3, 95% CI 1.04 to 5.47, P = 0.03

15 Conclusions Nurse practitioners can conduct pharmacological stress for MPS safely 65% of the high risk patients were successfully stressed by nurses There is a relationship between the nature of chest pain from the history and the presence of ischaemia The experienced stressor can often predict ischaemia from clinical observations and ECG during stress

16 Implications for future practice Nurse practitioners can be trained to perform cardiac stress effectively in a specialist centre The model for nurse education and training has also been used successfully in non-specialist centres We provide a programme for nurses to train in stress testing