Kari Pulkki

AIMS: To critically evaluate the clinical implications of the use of non-fasting rather than fasting lipid profiles and to provide guidance for the laboratory reporting of abnormal non-fasting or fasting lipid profiles. METHODS AND RESULTS: Extensive observational data, in which random non-fasting lipid profiles have been compared with those determined under fasting conditions, indicate that the maximal mean changes at 1-6 h after habitual meals are not clinically significant [+0.3 mmol/L (26 mg/dL) for triglycerides; -0.2 mmol/L (8 mg/dL) for total cholesterol; -0.2 mmol/L (8 mg/dL) for LDL cholesterol; +0.2 mmol/L (8 mg/dL) for calculated remnant cholesterol; -0.2 mmol/L (8 mg/dL) for calculated non-HDL cholesterol]; concentrations of HDL cholesterol, apolipoprotein A1, apolipoprotein B, and lipoprotein(a) are not affected by fasting/non-fasting status. In addition, non-fasting and fasting concentrations vary similarly over time and are comparable in the prediction of cardiovascular disease. To improve patient compliance with lipid testing, we therefore recommend the routine use of non-fasting lipid profiles, while fasting sampling may be considered when non-fasting triglycerides >5 mmol/L (440 mg/dL). For non-fasting samples, laboratory reports should flag abnormal concentrations as triglycerides ≥2 mmol/L (175 mg/dL), total cholesterol ≥5 mmol/L (190 mg/dL), LDL cholesterol ≥3 mmol/L (115 mg/dL), calculated remnant cholesterol ≥0.9 mmol/L (35 mg/dL), calculated non-HDL cholesterol ≥3.9 mmol/L (150 mg/dL), HDL cholesterol ≤1 mmol/L (40 mg/dL), apolipoprotein A1 ≤1.25 g/L (125 mg/dL), apolipoprotein B ≥1.0 g/L (100 mg/dL), and lipoprotein(a) ≥50 mg/dL (80th percentile); for fasting samples, abnormal concentrations correspond to triglycerides ≥1.7 mmol/L (150 mg/dL). Life-threatening concentrations require separate referral when triglycerides >10 mmol/L (880 mg/dL) for the risk of pancreatitis, LDL cholesterol >13 mmol/L (500 mg/dL) for homozygous familial hypercholesterolaemia, LDL cholesterol >5 mmol/L (190 mg/dL) for heterozygous familial hypercholesterolaemia, and lipoprotein(a) >150 mg/dL (99th percentile) for very high cardiovascular risk. CONCLUSION: We recommend that non-fasting blood samples be routinely used for the assessment of plasma lipid profiles. Laboratory reports should flag abnormal values on the basis of desirable concentration cut-points. Non-fasting and fasting measurements should be complementary but not mutually exclusive.

BACKGROUND: After reopening of the infarct-related coronary artery, cardiomyocytes continue to die during reperfusion. The mechanisms of cell death have been subject to debate. We studied whether an apoptotic type of cell death occurs in human acute myocardial infarction (AMI). METHODS AND RESULTS: We studied myocardial samples of eight patients who died of AMI and had patent infarct-related arteries at autopsy. Six of the patients had received initially successful thrombolysis. Extensive formation of DNA strand breaks, the typical biochemical feature of apoptosis, was detected with the use of the in situ DNA end-labeling method. Apoptotic cardiomyocytes were observed particularly in the border zones of histologically infarcted myocardium, whereas very few apoptotic cells were present in the remote noninfarcted myocardium. Internucleosomal fragmentation was confirmed by agarose gel electrophoresis of DNA isolated from the representative myocardial areas. CONCLUSIONS: This study provides evidence that in addition to overt necrosis, a subset of myocytes undergo apoptosis during ischemia-reperfusion injury. Apoptosis may provide a new target for cardioprotection during evolving AMI in humans.

Despite well-documented cardiotoxic effects, doxorubicin remains a major anticancer agent. To study the role of myocardial apoptosis following doxorubicin administration, male Wistar rats were exposed to 1.25, 2.5, and 5 mg/kg of i.p. doxorubicin and terminated on days 1-7 in groups of five. Doxorubicin caused a significant (P < 0.001) and dose-dependent induction of cardiomyocyte apoptosis at 24-48 h after the injection. Repeated injections of 2.5 mg/kg given every other day resulted in peaks of apoptosis at 24 h after each injection. However, no additive effect of repeated dosing was noted. In histological samples, alterations in the cytoskeletal apparatus with focal loss of contractile elements were seen after a single injection. Myocyte necrosis was absent. Thus, acute doxorubicin-induced cardiotoxicity involves cardiomyocyte apoptosis, a potentially preventable form of myocardial tissue loss.

We investigated the role of cardiomyocyte apoptosis in the remodeling of the left ventricle from 24 h to 12 wk after myocardial infarction in the rat. Infarct size planimetry, quantification of cardiomyocyte apoptosis, terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) methodology, and echocardiography (left ventricular diastolic diameter and ejection fraction) were performed. Sham-operated animals showed low rates of cardiomyocyte apoptosis (0.03%) and no change in diastolic diameter or ejection fraction during the study. Twenty-four hours after infarction, TUNEL positivity was high in the infarct areas (1.4%) and border zones (4.9%). It declined to 0.34% (P < 0.01 vs. sham) at 4 wk and 0.10% at 12 wk in the border zones. In the remote myocardium, cardiomyocyte apoptosis increased to 0.07% (P = 0.03 vs. sham) on day 1 and remained on the same level up to 4 wk. The increase in diastolic diameter 1-4 wk after infarction correlated (r = 0.60, P < 0.01) with cardiomyocyte apoptosis in the noninfarcted myocardium, which quantitatively contributed most (>50%) to the apoptotic cell loss by 4 wk.