Hyperlipidemia Prevents the Expected Reduction of Myocardial Ischemia on Repeated Balloon Inflations During Angioplasty

Interaction of Cardiovascular Risk Factors with Myocardial Ischemia/Reperfusion Injury, Preconditioning, and Postconditioning

“…The loss of the anti-ischemic effect of preconditioning (assessed by ST-segment elevation) in hyperlipidemia has been confirmed by two independent groups in patients undergoing repeated balloon inflations during coronary angioplasty (Kyriakides et al, 2002;Ungi et al, 2005). In one of these clinical studies, the loss of the anti-ischemic effect of early preconditioning was correlated with increased plasma cholesterol and LDL levels (Kyriakides et al, 2002). In contrast to the aforementioned studies, in rabbits fed a cholesterol-enriched diet for 8 weeks (Kremastinos et al, 2000), 6 weeks (Iliodromitis et al, 2006b), or 4 weeks (Jung et al, 2000) and in severely atherosclerotic ApoE/LDLr Ϫ/Ϫ double knockout mice fed an atherogenic diet for 6 to 8 months ) and 7 to 9 months (Tokuno et al, 2002) the infarct sizelimiting effect of classic preconditioning was not attenuated.…”

“…Furthermore, Juhasz et al (2004) showed that increasing the number of preconditioning cycles even aggravated infarct size in rabbit isolated subjected to ischemia/reperfusion after 8 weeks of experimental hypercholesterolemia. The loss of the anti-ischemic effect of preconditioning (assessed by ST-segment elevation) in hyperlipidemia has been confirmed by two independent groups in patients undergoing repeated balloon inflations during coronary angioplasty (Kyriakides et al, 2002;Ungi et al, 2005). In one of these clinical studies, the loss of the anti-ischemic effect of early preconditioning was correlated with increased plasma cholesterol and LDL levels (Kyriakides et al, 2002).…”

Experimental hyperlipidaemia does not prevent preconditioning and it reduces ischemia-induced apoptosis

“…Preliminary studies have reported that short-term cholesterol feeding may render the myocardium more susceptible to ischemia-reperfusion injury, whereas prolonged hypercholesterolemia does not appear to harm and may even protect the myocardium from reperfusion injury [8][9][10][11]. The cardioprotection conferred by classical preconditioning was shown to be lost in hypercholesterolemic rabbits [12], rats [8,13] and in humans [14]. In contrast to the above studies, the size-limiting effect of the infarct by preconditioning was not attenuated in hyperlipidaemic mice [15,16] and rabbits [11].…”

Does the Treatment of Both Hypertension and Cardiac Hypertrophy Not Only Prevent But Also Treat Acute Myocardial Infarction?

“…5 The loss of the anti-ischemic effect of IP in hyperlipidemia has been also confirmed in patients undergoing repeated balloon inflations during coronary angioplasty, and the loss of the antiischemic effect of IP correlated with plasma cholesterol and low-density lipoprotein levels. 6 A decrease in cardiac nitric oxide (NO) bioavailability and ecto-5'-nucleotidase activity 5 have been shown to contribute to loss of IP in hyperlipidemic animal models. Recently, Giricz et al reported that hyperlipidemia attenuates the infarct size-limiting effect of IP via cardiac matrix metalloproteinase-2 activation.…”