Category Archives: coronary artery disease

Effect of PCI on Long-Term Survival

From The Journal of Family Practice

Effect of PCI on Long-Term SurvivalOutcomes in patients with stable ischemic HD

December 1, 2015

There was no difference in survival between an initial strategy of PCI plus medical therapy and medical therapy alone after extended 15-year follow-up in patients with stable ischemic heart disease, according to extended survival information for 1,211 patients. Median duration of follow-up for all patients was 6.2 years; the median duration of follow-up for patients at the sites that permitted survival tracking was 11.9 years.

Researchers found:

• 561 deaths occurred; 180 during the follow-up period in the original trial and 381 during the extended follow-up period.

• There were 284 deaths (25%) in the PCI group and 277 (24%) in the medical therapy group (aHR, 1.03).

Citation: Sedlis SP, Hartigan PM, Teo KK, et al. Effect of PCI on long-term survival in patients with stable ischemic heart disease. N Engl J Med.2015;373:1937-1946. doi: 10.1056/NEJMoa1505532.

Commentary: The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial compared a strategy of optimal medical therapy for advanced coronary artery disease versus optimal medical therapy plus percutaneous coronary intervention (PCI) and found no difference in outcome between these 2  groups. This was a landmark trial and has influenced guidelines and changed the practice of interventional cardiology. The current study follows patients from the original COURAGE cohort for up to 15 years and continues to show no survival advantage in either group. In addition, no high-risk subgroup of patients has been identified that showed a survival benefit from PCI compared with optimal medical therapy alone in the original study or in the extended cohort. This study adds further evidence that PCI can be used for treatment of angina that does not respond to medical treatment but will not offer a survival advantage over optimal medical therapy. —Matthew Sorrentino, MD

New ACC/AHA Guidelines for Statins: Calculator Overestimates Risk

Last week the American College of Cardiology/American Heart Association (ACC/AHA) published guidelines on cardiovascular risk assessment, and lifestyle changes and cholesterol-lowering treatment to reduce cardiovascular risk (J Am Coll Cardiol 2013 Nov 12 early online PDFCirculation 2013 Nov 12 early online PDF). Many DynaMed topics have been updated to incorporate these new guidelines and replace the 2002 National Cholesterol Education Program (NCEP) guidelines. For the Statins for prevention of cardiovascular disease topic 3 major issues are of exceptional interest.

1. The ACC/AHA guidelines do not identify “target” cholesterol levels as the goal when treating dyslipidemia. 

This is now consistent with guidelines from other countries (such as 2008 NICE guidelines in the United Kingdom) which recognize benefit in treatment from overall risk reduction but not specific benefit from treating to target levels. The ACC/AHA guidelines (unlike the NICE guidelines) recommend monitoring cholesterol levels on treatment, especially for the purpose of monitoring and encouraging treatment adherence.

2. The threshold for when statin therapy is recommended are much lower in the ACC/AHA guidelines than in the NICE guidelines.

The ACC/AHA guidelines recommend treatment with a 10-year risk for cardiovascular disease events > 7.5% and suggest treatment may be reasonable at a risk of 5%-7.5%, while NICE recommends statins therapy for adults with a 10-year risk > 20%. Both groups recommend statin therapy for most patients with diabetes or established cardiovascular disease.

3. Use of Pooled Cohort Equations is proposed for estimating the 10-year risk of cardiovascular disease events.

The Pooled Cohort Equations appear to overestimate cardiovascular risk. This was found in comparison to actual event rates in the 2 cohorts used for independent external validation of these equations, and was also reported in 3 large primary prevention cohorts (Lancet 2013 Nov 19 early online PDF). The DynaMed topic on Cardiovascular risk prediction includes multiple approaches for risk estimation, including links for their use and evidence supporting them.

To put this into perspective for patients:

To understand the benefits for an individual patient it is useful to estimate the absolute benefit of treatment for that patient. This can be understood as the number of patients who would need to be treated for 5 years to prevent one adverse outcome (NNT). We made estimates of the NNT for selected major adverse outcomes at different levels of predicted 10-year risk, using estimates for risk reductions derived from systematic reviews:

NNT for Statins for 5 Years:
10-year risk of CVD events 5-year NNT for CVD events 5-year NNT for myocardial infarction 5-year NNT for stroke 5-year NNT for mortality
5% 160 278 910 *
7.5% 108 186 606 *
10% 80 140 456 *
15% 54 94 304 334
20% 40 70 228 250
Abbreviations: CVD, cardiovascular disease; NNT, number needed to treat (to prevent 1 outcome)

* no apparent mortality reduction in lowest-risk patients (BMJ 2013 Oct 22;347:f6123)

Courtesty: DynaMed

 The guidelines consider risks for adverse effects to be minimal. Randomized controlled data find low rates of serious adverse events, such as rate of myopathy 1 per 10,000 person-years, and a modest increase in diabetes (NNH 255 over 4 years [Lancet 2010 Feb 27;375(9716):735]) Observational studies have reported up to 17.4% rates of statin-related adverse events (Ann Intern Med 2013 Apr 2;158(7):526)

For more information, see the Statins for prevention of cardiovascular disease topic in DynaMed.

References:

Routine stress testing after negative Troponin tests seldom helpful

Clinical question: What is the diagnostic yield of performing routine stress testing in patients who have tested negative for acute coronary artery syndrome?

Bottom Line:  Fewer than 1% of patients who present to the ER with acute chest pain and then undergo routine provocative cardiac testing after 2 sets of negative serum troponin results are likely to benefit from angioplasty (American Heart Association [AHA] class I or IIa). False-positive results will be common.(True positive rate 51.2%) (LOE = 2b)

Reference

Hermann LK, Newman DH, Pleasant WA, et al. Yield of routine cardiac testing among patients in an emergency department-based chest pain unit. JAMA Intern Med 2013; 173(12):1128-1133.

Study Design: Cohort (retrospective)

Funding: Self-funded or unfunded

Setting: Emergency department

Allocation: Unknown

Synopsis: The AHA recommends provocative testing (eg, stress testing) in patients with acute chest pain who have negative biomarker results, with the idea that it will identify patients who may benefit from revascularization. The researchers conducting this study identified all patients (N = 4181) without previously identified coronary artery disease who presented to an emergency department over a 6-year period. All included patients had been ruled out for acute coronary syndrome and then had exercise stress testing (n = 512) or myocardial perfusion imaging (n = 3669) while still in the emergency department. Of these patients, 470 (11.2%) had inducible myocardial ischemia. Most were managed medically, but 26.2% of them were deemed to require coronary angiography to determine whether they had obstructive disease that would benefit from revascularization. Of this group, a total of 63 had obstructive disease, but only 28 patients had disease that would benefit from revascularization (AHA class I or IIa). As a result, the true positive rate was only 51.2% for patients undergoing provocative testing and subsequent angiography. Only 0.7% of patients who underwent provocative testing would have benefited from intervention, and an equal percentage had obstructive disease that would have been harmed by catheterization (eg, AHA class III).

Allen F. Shaughnessy, PharmD, MMedEd
Professor of Family Medicine
Tufts University
Boston, MA