Can negative cardiac effect of proton pump inhibitor and high-dose H2-blocker have clinical influence on patients with stable angina?

Background: Aspirin and anti-platelet drugs are used commonly for patients with coronary heart disease. Proton pump inhibitor (PPI) and high-dose H2-blocker were recommended for preventing NSAIDs-related ulcer. Previously H2-blocker reported to have some negative cardiovascular effects. Additionally, a recent in vitro study showed that PPI reduced cardiac contractility. In this study, we evaluated whether chronic administration of PPI and high-dose H2-blocker affects left ventricular function.
Method: Fifty-two stable angina patients were enrolled and classified into PPI group ([P]; lansoprazole: 15 mg/day, n=28), H2-blocker group ([H]; famotidine: 40 mg/day, n=8), and control ([C]; none or mucosal-defense drug, n=16). Eligible patients showed normal cardiac function in initial catheterization without administrated PPI or H2-blocker. They received percutaneous coronary intervention and follow-up catheterization. We compared changes in ejection fraction (EF: %), end diastolic/systolic volume index (EDVI/ESVI: ml/m(2)), and peak positive/negative dp/dt (+/-dp/dt: mmHg/s) in left ventricular angiography series.
Result: There were no significant differences among three groups regarding patient characteristics, backgrounds of angiographic and intervention, except for fewer smokers in [C]. Other drugs such as beta- and Ca-blocker did not have effects on cardiac function except for aspirin during 255+/-115 days follow-up. Rate of EF changes significantly decreased in [P], and tended to decrease in [H] (C: 3.8+/-9.8%, H: -1.6+/-7.6%, P: -2.1+/-5.9%; p<0.05 for [C] vs. [P]). Those of ESVI changes were significantly greater in [P], and tended to be greater in [H] (C: -4.5+/-16.2%, H: 4.9+/-15.5%, P: 7.3+/-16.2%; p<0.05 for [C] vs. [P]), though, EDVI changes' were similar (C: 2.5+/-8.9%, H: 2.6+/-3.6%, P: 1.6+/-6.1%; p=ns). Rate of +/-dp/dt-changes tended to decrease in [H] (+dp/dt: C: 3.9+/-15.5%, H: -10.0+/-25.2%, P: 0.3+/-19.6%; p=ns, -dp/dt: C: -0.1+/-19.5%, H: -8.5+/-20.4%, P: 5.7+/-27.7%; p=ns).
Conclusion: In this study, PPI and high-dose H2-blocker have EF-reducing tendency. However, these changes were small and these drugs seemed to exhibit little influence clinically.