AAA screening recommendation update

the US prev services taskforce (USPSTF) updated their 2005 recommendation on abdominal aortic aneurysm (AAA) screening (see AAA screening USPSTF annals 2014 in dropbox, or doi:10.7326/M14-1204).  bottom line: they recommend --

    --"1-time screening for AAA with ultrasonography in men aged 65 to 75 who have ever smoked" (B recommendation) -- "ever-smoker" is anyone who has smoked >100 cigarettes in his/her lifetime

    --"clinicians selectively offer screening for AAA in men aged 65 to 75 who have never smoked" (C recommendation) -- ie net benefit of screening is small, so assess medical history/risk factors (eg other vascular aneurysms, CAD, cerbrovasc disease, hypercholesterolemia, obesity, hypertension), family history of AAA, personal values. of note, reduced AAA risk in african-americans, latinos, and those with diabetes.

    --"current evidence is insufficient to assess the balance of benefits and harms of screening for AAA in women aged 65 to 75 who have ever smoked" (I statement)

    --"against routine screening for AAA in women who have never smoked" (D recommendation)

    --there are evident harms in screening, with notable autopsy study from Mass General Hosp finding that 75% of 473 patients with AAA (41% >5.1cm) died of unrelated causes. one study also found that women had higher surgical mortality than men (7% vs 5%), though a meta-anal also found that women had higher risk of rupture with AAAs of the same diameter. not surprisingly, screening leads to doubled the rate of surgeries for AAA in men

    --screening is one time as noted, with repeated ultrasound every 3-12 months if AAA 3-5.4cm and surgery if larger or if grow >1cm/yr. short-term follow up of meds (eg b-blockers) does NOT seem to decrease rate of AAA growth

the issue is that screening works, per 4 large RCTs, which in men decreases AAA-specific mortality by 42-66%, beginning after 3 years and persisting up to 15 years. but the prevalence of AAA varies by group: highest for men who ever-smoked (6-7%), less in  men who never smoked (2%), even less in women aged 70 who ever-smoked (0.8%), then lowest in women who never smoked (0.03-0.6%).  one trial in women who had smoked found no diff in AAA rupture rates, AAA-specific mortality or all-cause mortality -- but study underpowered. USPSTF does comment on the importance of risk reduction (stopping smoking, ??utility of statins -- though they are recommended anyway in this group). so, the biggest change is adding the selective screening for men who never smoked from "no recommendation" to "selective screening" (confusing, since they still give C recommendation, but to my reading they are more open to selective screening.  however, not sure exactly what that means, since it is remarkably rare to see someone 65-75 years old with none of the risk factors noted above. and, the recommendation for women has gone from not screen to indeterminant in those who ever-smoked. ie, a trend to liberalizing the recommendations, but not really clear what they mean regarding implementation. any man aged 65 who never smoked but with hyperlipidemia or hypertension???