Implantable Cardiac Monitors for Atrial Fibrillation (AF) Detection: Ready for Routine Use?

Transcription

1 Implantable Cardiac Monitors for Atrial Fibrillation (AF) Detection: Ready for Routine Use? Helmut Pürerfellner, MD, Assoc. Prof. Saint Elisabeth s Sisters Hospital Academic Teaching Center Linz/Austria

2 Disclosures Consultancy for BRC (Medtronic, NL) Steering Committee Insight (R)XT Registry (Reveal XT Implantable Loop Recorder, Medtronic)

3 Outline Symptomatic vs Asymptomatic AF Intermittent vs Continuous Monitoring of AF AF and Stroke Implantable Loop Recorder (ILR) Current/Future Indications for AF Monitoring

4 Two Kinds of AF Patients Asymptomatic AF Symptomatic non-af

5 Prevalence of Asymptomatic AF Page (Circulation 1994) 12:1 ratio based on 5 days with 24-h Holter (i.e., 7.7% of AF symptomatic) Israel (JACC 2004) 38% of pts with episodes of AF >48h were completely asymptomatic Continuous monitoring with AT500 pacemaker Strickberger (Heart Rhythm 2005) 6% of AF symptomatic; 17% of symptoms due to AF Continuous monitoring with AT500 pacemaker Hindricks (Circulation 2005) Before ablation, 5% of patients had only asymptomatic AF (7-day Holter) After ablation, 37% of patients had only asymptomatic AF (7-day Holter) Quirino (PACE 2009) 19% of AF symptomatic; 21% of symptoms due to AF Continuous monitoring with Vitatron pacemaker

6 Relationship between Symptoms and AF in ECG Transmissions Vasamreddy et al. J Cardiovasc Electrophysiol 2006;17:

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8 Continuous AF Monitoring More intensive monitoring results in more AF detection In pts. with a pacemaker or ICD implanted the device provides objective, accurate AF information*

9 ECG/Holter vs. Pacemaker Diagnostics 254 pts. with a DDD pacemaker received 24-h Holter monitoring at 6 weeks and ECG recording at 6, 26 and 52 weeks postimplant AT documentation in 15% (ECG) and 54% (pacemaker EGM) Israel C et al. PACE 2006:29:

10 Continuous vs. Intermittent AF Monitoring Study comparing intermittent and symptom-based monitoring with continuous monitoring in 574 pts. with MDT AT500 PM Intermittent and symptom-based monitoring is highly inaccurate for identifying pts. with any or long-duration AF Ziegler et al. Heart Rhythm 2006;3:

11 Pacemaker Diagnostics 12 pts. with a MDT AT500 implanted were monitored pre- and post PV ablation PV ablation: reduction in AT burden (3.2 to 0.2 h/day) and AT frequency (6.4 to 0.3 episodes/day, p=0.09) Reductions in AT burden were associated with QoL improvements Pürerfellner et al. PACE 2004;27:

12 Long Term Follow-up of AF Ablation Very late Recurrences Blanking Period Martinek, Pürerfellner. J Cardiovasc Electrophysiol 2007;18:

13 Long Term Follow-up of AF Ablation Martinek, Pürerfellner. J Cardiovasc Electrophysiol 2007;18:

14 Newly Detected AF in Patients with a History of Thromboembolic Events Jabaudon (Stroke 2004) 24 hour Holter (5.0%) Bansil (J Stroke Cerebrovasc Dis 2004) 48 hour Holter (4.0%) Jabaudon (Stroke 2004) 7 day Holter (8.1%) Tayal (Neurology 2008) 21 day monitor (23%*) 5.4% * 85% of episodes were <30 seconds in duration Ziegler (Stroke 2010) 1.2 years continuous monitoring (28%*) * 5 minute duration criteria vs. 3.1% vs. 4.3% vs. 6.1% vs. 10.9%

15 Newly Detected AF via Implantable Devices in Patients with a History of Thromboembolic Events Ziegler et al. Stroke 2010;41:

16 Newly Detected AF via Implantable Devices in Patients with a History of Thromboembolic Events Ziegler et al. Stroke 2010;41:

17 Newly Detected AF via Implantable Devices in Patients with a History of Thromboembolic Events Ziegler et al. Stroke 2010;41:

18 Stroke rate in % AF and Stroke Risk Factors Stroke rate increases exponentially with the score: y = e x R 2 = CHADS 2 score V. Fuster. Circulation 2006; 114: e257-e354

19 Does AF Burden Matter? MOST Substudy: Circulation 2003 AHRE >5 minutes detected by pacemakers in patients with SND identify patients that are more than twice as likely to die or have a stroke. Capucci: JACC 2005 The risk of stroke (adjusted for risk factors) was 3.1 times higher in patients with device-detected AF longer than 24 hours. Botto: JCE 2009 Stroke risk is a function of both AF burden and CHADS 2 score. Low burden/high CHADS 2 and high burden/low CHADS 2 both have high risk. TRENDS: Circulation: Arrhythmias and EP 2009 High burden (>5.5 hrs) on any day during the preceding 30 days doubles the risk for thrombo-embolic event independent of other stroke risk factors.

20 CHADS2 Score, AF Duration and Stroke Risk CHADS 2 score No AF at FU (AT/AF < 5 min in 1 day) 1.7% 0% 0% 25% 5 min < AT/AF Episodes < 24 h 1.8% 1.3% 2.4% 0% AT/AF Episodes > 24 h 0% 4.4% 4.4% 33% (3 out of 351 Pts) 0.8 % vs. 5 % (11 out of 217 Pts) p = Botto et al. J Cardiovasc Electrophysiol, 2009;20:

21 XPECT Reveal XT Performance Trial XPECT study is a prospective, non-randomized, multicenter (24 centers), international, post-market study. Reveal performance was compared to the surface ECG Holter recordings, as the standard in clinical practice. Primary Objective: Accuracy of Reveal XT to detect AF. Looprecorder vs. external Holter. Patient Population -Pts scheduled for PV ablation -Pts symptomatic after PV ablation with symptoms attributable to AF -Pts with documented paroxysmal AF. Hindricks,, Pürerfellner. Circ Arrhythm Electrophysiol 2010;3; ;

22 % 100 AF Episode Detection ,8 92,1 92,3 92,9 Sensitivity 73,6 79,6 79,4 81,2 PPV 2 min 6 min 10 min 20 min Negative Predictive Value 97.4%! As the duration of the AF episode increases, the Sensitivity, NPV, and PPV for AF episode detection also increase. A plateau is reached beyond 6 minutes: 6 minutes is the recommended setting for AF detection. Hindricks,, Pürerfellner. Circ Arrhythm Electrophysiol 2010;3; ;

23 Integration of Multiple Parameters

24 AF Pts Exceeding VR (%) Telemonitoring for Rate Control in AF Via the Medtronic CareLink Network, ventricular rate while in AF was assessed in 56,299 ICD or CRT-D patients with >5 minutes of AF 100% 80% 60% Persistent ( PER 37% of pts.) Paroxysmal ( PAF 63% of pts.) Although relatively well controlled in the majority of persistent AF patients, mean ventricular rate during AF is poorly controlled in the majority of paroxysmal AF patients 40% 20% Mean Ventricular Rate (bpm) Mean ventricular rate during AF was >80 bpm in 74% of PAF patients vs. 34% of PER patients Ziegler et al. HRS 2009

25 Telemonitoring in Asymptomatic AF Patients with alerts for asymptomatic AF No further action taken = 21% Unscheduled follow-up visit = 79% AAD started or modified = 38% OAC introduced = 36% Anti-platelets introduced = 5% External cardioversion = 17% Median time to first intervention was 50 days (148 days before scheduled follow-up) Early detection of AF allowed early reaction to optimize medical treatment Ricci et al. Europace 2009;11:54-61

26 IMPACT Study Ip et al. Am Heart J 2009;158:

27 Summary 1. Poor correlation between symptoms and AF episodes. a) AF episodes may be asymptomatic b) Symptoms may not be related to AF episodes 2. Intermittent monitoring leads to underdetection of AF. a) Wrong decisions concerning AAD therapy, and anticoagulation b) Wrong evaluation of therapy success 3. Continuous monitoring is an indispensable tool resulting in accurate and more objective information about the AF status and the efficacy of treatment methods. 4. New implantable devices are capable of identifying AF with a good sensitivity and negative predictive value. 5. Accurate AF detection by implantable devices could lead to new therapeutic strategies, a better understanding of AF behavior, and might change treatment paradigms in the future ( extended pill in the pocket / start-stop-restart algorithm )

28 Implantable Cardiac Monitors for Atrial Fibrillation Detection: Ready for Routine Use? Technically: Yes, however there is still room for improvement (PPV for AF detection, size of the device, longevity, automatic alerts) Clinically: Yes, for relevant subgroups (cryptogenic stroke), investigational use (AF ablation, AF and HF patients, drug studies) in ongoing registries/studies No, in general (evidence for reduction in clinical endpoints, cost effectiveness to be assessed )