Long-Term Drug Therapy Following Carotid Endarterectomy Aimed at Reducing Major Adverse Cardiovascular Events

Background: Timely carotid endarterectomy (CEA) reduces the risk of future stroke. This benefit is maximized with lifelong drug therapy aimed at reducing further major adverse cardiovascular events (MACEs), including stroke. Studies suggest that around half discontinue these drugs within 12 months. To assess if this is the case following CEA, we considered the MACE-reducing drugs prescribed several years later and compared this with the drugs they were prescribed at CEA. Methods: The electronic primary care records of 347 post-CEA patients a mean of 108 (range 43-185) months after surgery were interrogated. The prescriptions of generic MACE-reducing drugs (antithrombotic, lipid-lowering, antihypertension and diabetes) of the 187 alive were compared with their prescriptions at CEA and with the last prescription of the 160 who had died before the late review. The post-CEA incidence of further MACE in survivors was determined. Results: At late review, fewer of the post-CEA patients alive were taking antiplatelet drugs (143, 76% vs. 170, 91% P < 0.01), but more were fully anticoagulated (37v4 P < 0.01) when compared with prescriptions at CEA. Overall, there was no change in antithrombotic drug prescription rates (167, 89% vs. 172, 92%). Lipid-regulating drugs were well prescribed both at late review and at CEA (173, 93% vs. 169, 90%). The number prescribed antihypertension drugs was significantly higher at late review than at CEA (166, 89% vs. 67, 35% P < 0.01). The number treated for diabetes was similar (64, 34% vs. 42, 23%). There was no difference in the numbers of any of the MACE-reducing drugs prescribed between those who had survived to late review and those who had not. At late review, of those alive, there were 22 (12%) new strokes, and 24 (14%) had developed new or worsening ischemic cardiac symptoms. Conclusions: We found a higher than expected prescription rate of MACE-reducing drugs many years after CEA. This finding may be due, in part, to the nationalized health service in the United Kingdom.