Blood Pressure and Atrial Fibrillation: a Combined AF-CHF and AFFIRM Analysis

1. Blood Pressure and Atrial Fibrillation: a Combined AF-CHF and AFFIRM Analysis Maxime Tremblay-Gravel, MD*; Michel White, MD*; Denis Roy, MD*; Hugues Leduc, MSc*; D. George Wyse, MD, PhD†; Julia Cadrin-Tourigny, MD*; Laurent Macle, MD*; Marc Dubuc, MD*; Jason Andrade, MD*; Lena Rivard, MD*; Peter G. Guerra, MD*; Bernard Thibault, MD*; Mario Talajic, MD*; Paul Khairy, MD, PhD* From the *Montreal Heart Institute, Université de Montréal, Montreal, Canada; and †LibinCardiovascular Institute, Calgary, Canada Results Introduction Discussion • 2715 patients, 68±8 years, 67% male, were followed for 40.8±15.7 months • High blood pressure canpromote AF throughdifferentmechanisms • Increasedafterload leads to leftventricularhypertrophy, pressure overload, and left atrial wall stretch, withelectrical and structural remodelingthatensuescreating a favorable substrate for AF. • Activation of the renin-angiotensin system mayinducefibrosis and alter atrial electrophysiology.3 • Higher SBP (>140 mmHg) wasassociatedwith a greaterpropensity for AF only in patients with LVEF ≤40%. Hypothetically, thisfindingmaybe due to enhancedsensitivity to afterload in the setting of HF • Withsystolicdysfunction, increased LV filling pressures compensate for higher SBP in order to maintaincardiac output, therebypredisposing to atrial remodelingand AF • In contrast, filling pressures in the normal heart are onlyminimallyaffected by changes in afterload • Lower SBP (<120 mmHg) did not confer protection against AF, perhaps due in part to its association withadvancedheartdisease4 • Ratherthanreflectinglowsystemicvascularresistance, lowblood pressure mayresultfromseverelyimpairedcontractility, alongwith congestion and highfilling pressures, whichmaypromoteAF5 • Althoughhypertension is an establishedrisk factor for atrial fibrillation (AF), the relationshipbetweensystolicblood pressure (SBP), recurrent AF, and AF burdenislesswellunderstood. Moreover, the interplaybetween SBP and AF maydiffer in patients with and withoutleftventriculardysfunction. • The objective of thisstudywas to evaluate the impact of blood pressure on the ability to maintain sinus rhythm (SR) witha rhythm control strategy, in patients with and withoutheartfailure (HF) Time to recurrence of AF* LVEF >40% Adjusted P=0.755 Survival Free of AF Recurrence SBP < 120 mmHg SBP 120-140 mmHg SBP > 140 mmHg Time in months Methods • In patients with LVEF >40%, baseline SBP was not associated with recurrent AF in multivariate Cox regression analyses Time to recurrence of AF* LVEF ≤40% • A post hoc combined analysis was conducted on patients randomized to rhythm control in AFFIRM1and AF-CHF2studies • We assessed the impact of SBP on AF recurrence rates and proportion of time spent in AF (AF burden) • Patients were classified according to baseline SBP (<120 mmHg, 120-140 mmHg, >140 mmHg) and left ventricular ejection fraction (LVEF; ≤40%, >40%) Adjusted P=0.012 Survival Free of AF Recurrence Conclusion SBP < 120 mmHg SBP 120-140 mmHg SBP > 140 mmHg • In patients with non-permanent AF randomized to rhythm control, recurrent AF was not modulated by SBP in the absence of left ventricular dysfunction • In patients with LVEF ≤40%, a “U-shaped” pattern was identified, with higher (>140 mmHg) and lower (<120 mmHg) SBP associated with increased risk of AF recurrence and AF burden compared to SBP 120-140 mmHg All patients in AFFIRM and AF-CHF (n=5436) Time in months Rate-control arm (n=2721) • In patients with LVEF ≤40%, the AF recurrence rate was higher in those with a SBP >140 mmHg compared to 120-140 mmHg [HR 1.49; 95% CI (1.14 to 1.95)] • SBP <120 mmHg was associated with a trend towards a higher rate of AF recurrence compared to SBP 120-140 mmHg [HR 1.13; 95% CI (0.91 to 1.41)] Rhythm-control arm (n=2715) LVEF not available (n=513) LVEF available (n=2202) References LVEF > 40% (n=1313) LVEF ≤ 40% (n=889) Proportion of time spent in AF* (%) SBP <120 (n=340) SBP <120 (n=507) AFFIRM-Investigators. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med 2002;347:1825-33. Roy D, Talajic M, Nattel S, et al. Rhythm control versus rate control for atrial fibrillation and heartfailure. N Engl J Med 2008;358:2667-77. Go O, Rosendorff C. Hypertension and atrial fibrillation. CurrCardiolRep 2009;11:430-5. Aaronson KD, Schwartz JS, Chen TM, Wong KL, Goin JE, Mancini DM. Development and prospective validation of a clinical index to predictsurvival in ambulatory patients referred for cardiac transplant evaluation. Circulation 1997;95:2660-7. HolubarschC, RufT, Goldstein DJ, et al. Existence of the Frank-Starlingmechanism in the failinghumanheart. Investigations on the organ, tissue, and sarcomerelevels. Circulation 1996;94:683-9. SBP 120-140 (n=492) SBP 120-140 (n=234) • Similarly, proportion of time spent in AF was influenced by SBP only in patients with LVEF ≤40%. AF burden was lowest in patients with SBP 120-140 mmHg. SBP >140 (n=479) SBP >140 (n=148) *All values wereadjusted in multivariatemodels