Studies Flashcards
Summarize main pacing trials that influence today´s best practice
Danish pacemaker trial: patients with SND randomized to either AAI or VVI pacing: showed improved survival and less HF in the AAI group.
The Canadian Trial of Physiologic Pacing (CTOPP): compared DDDR vs VVIR and AAIR: physiologic pacing (DDDR/AAIR) was associated with reduced rate in development of chronic AF; however there was no significant improvement in QOL with DDDR pacing.
UK Pacing and Cardiovascular Events (UKPACE): compared DDD vs VVI in patients >70 yrs who required pacing for 2nd or 3rd degree AV block: showed no significant difference in primary endpoint of all-cause mortality or in secondary endpoint of cardiovascular deaths, AF, HF hospitalizations, strokes.
Mode Selection Trial (MOST): randomized 2010 patients with SND to either VVI or DDD pacing: showed no difference in mortality; but lower incidence of AF and reduced signs of HF with DDD pacing. The study showed that in patients with normal baseline QRS duration, the cumulative RV pacing is a strong predictor of HF hospitalization and AF, even when the AV synchrony was preserved.
Dual Chamber and VVI Implantable Defibrillator (DAVID) trial: designed to assess the effect of dual-chamber (set DDD 70 bpm) vs VVI ICD but no indication for brady pacing (set VVI 40 bpm): showed that dual-chamber pacing offered no advantage and actually increased the endpoint of death and HF hospitalization.
DAVID II trial: tested AAI 70 bpm vs VVI 40 bpm: no difference in mortality, HF, AF, or QOL between the two groups.
MADIT II trial: patients with MI and reduced EF < 30% received either and ICD or conventional pacemaker: those with an ICD had significant reduced mortality, however if those in whom the VP >50% the mortality benefit was attenuated such that after 4 years, there was no difference in mortality.
What did the INTRINSIC RV study test and show?
The study tested the hypothesis that RV minimization algorithm (AV search hysteresis) was noninferior to VVI backup pacing, showing no difference in mortality.
What did the SAVE-PACe trial show?
SAVE-PACe trial randomized 1065 patient with SND to either DDDR vs DDDR with RVP minimization algorithms, showing no difference in mortality or HF between the two groups. There was also an increase in AF with minimized RV pacing.
What did the DANPACE trial show?
In DANPACE trial patients with SND were randomized to either AAIR vs DDDR. There were no differences in mortality and HF occurrence and surprisingly there was greater incidence of AF in the AAI group.
What did the Managed ventricular pacing (MVP) trial show?
It evaluated atrial pacing plus ventricular backup pacing at 60 bpm vs ventricular backup pacing at 40 bpm in 1030 patients: the study was terminated prematurely because those with PR > 230 msec had increased mortality and and HF occurrence.
What did the Prefer for Elective Replacement MVP study show?
Randomized patient who needed device replacement that required >40% RV pacing without CRT indication or CHB to either MVP or DDD modes. It showed no significant difference in death and cardiac hospitalization. However this study was performed in a population of low number of patients with NYHA class III or IV, reduced EF or high AV block thus may not be reflective of the effects of RV minimization in sicker patients.
What did the Protect-Pace trial show?
This randomized, multicenter trial sought to address RV lead position on LVEF. It evaluated 240 patients with high grade AV block and normal EF randomized to either RV apical pacing vs high RV septal pacing. At 2 yr follow-up the decrease in LVEF was the same in both groups with no difference in mortality, AF and HF hospitalization.
Studies in CRT
One study showed that LV pacing only (without simultaneous RV pacing) produced acute LV and systemic hemodynamic benefits similar to BiVP pacing. It also showed superior RV hemodynamic to BiVP.
Kass et al study also showed that at an AV delay of 120 ms BiVP and LV only pacing both improved LV hemodynamics with LV only pacing being superior.
