Angiotensin-converting-enzyme (ACE) inhibitors reduce morbidity and mortality in patients with chronic heart failure and systolic left-ventricular dysfunction, as well as in patients who have had a myocardial infarction . These drugs, in familial hypercholesterolemic (FH) patients treated with low-density lipoprotein (LDL) apheresis using dextran sulfate-cellulose (DSC) columns, can cause marked hypotensive crises . These reactions are probably triggered by elevated generation of bradykinin due to contact of blood with polyanionic DSC (a potent activator of the contact activating system of coagulation factors), and bradykinin's diminished inactivation due to ACE inhibitors . These adverse reactions are called anion-blood contact reaction (ABC reaction). Losartan is the first of a new class of drugs called angiotensin (AII)-antagonists. This drug acts, blocking selectively the AT1 receptor and preventing the linking of AII to the site of action . Two FH patients affected by CHD, in therapy with DSC-LDL apheresis, who in past years experienced ABC reaction during treatment with enalapril, have been treated with Losartan (Neolotan, Neopharmed, Rome, Italy) 50 mg, one tablet once a day. No symptoms of hypotension, flushing, dyspnea, or bradycardia have occurred during and after apheresis treatment. In conclusion, these data support the proposed mechanism of the ABC reaction due to ACE-inhibitors. Furthermore, losartan seems to be well tolerated in FH patients affected by CHD, and it permits by-pass of the problems inherent to the use of conventional inhibitors of ACE, in patients treated with LDL-apheresis with DSC columns.