A
30-year study of patients who underwent successful percutaneous coronary
intervention (PCI) shows that those who quit smoking appear to live longer than
those who continue to smoke, according to a study published online July 29,
2013, ahead of print in the American Journal of Cardiology. Furthermore,
long-term all-cause mortality rates of quitters are similar in the end to those
of nonsmokers.
Investigators
led by Ron T. van Domburg, PhD, of Erasmus Medical Center (Rotterdam, The
Netherlands), analyzed life expectancy for 856 consecutive patients who
underwent PCI between 1980 and 1985 and for whom 30-year follow-up data,
including self-reported smoking status at 1 year, were available. Patients were
divided into 3 groups:
- Nonsmokers
- Quitters
- Persistent smokers
Quitters
Win in the End:
Overall,
there were 14,977 patient-years of follow-up (median 19.5 years). The
self-reported smoking rate fell from 61% prior to PCI to 36% at 1 year.
The
cumulative 30-year survival rate was higher among those who quit smoking, as
was life expectancy, which showed a 2-year advantage for quitters (table 1).
Table
1. Survival and Life Expectancy:
|
|
Persistent
Smokers
(n = 287)
|
Quitters
(n = 210)
|
P Value
|
|
30-Year Survival
|
14%
|
29%
|
0.005
|
|
Life Expectancy, years
|
16.4
|
18.5
|
< 0.0001
|
Quitters had similar all-cause mortality rates compared with nonsmokers, and
both of these groups had lower mortality than persistent smokers (adjusted HR
0.57; 95% CI 0.46-0.71 and adjusted HR 0.42; 95% CI 0.34-0.52, respectively).
Other
independent predictors of long-term all-cause mortality were:
- Multivessel disease (adjusted HR 1.45; 95% CI 1.19-1.75)
- Previous MI (adjusted HR 1.27; 95% CI 1.06-1.53)
- Hypertension (adjusted HR 1.37; 95% CI 1.14-1.64)
Dated
Yet Relevant:
According
to the study authors, although all the PCI procedures were performed in the
pre-stent era, the findings are in agreement with prior research showing
substantial reductions in all-cause mortality and nonfatal myocardial
reinfarctions with smoking cessation in patients with coronary heart disease.
“Although
it remains to be seen to what extent smoking cessation will benefit current
patients, there are no indications that the unfavorable effect of smoking can
be made undone using novel treatment methods,” they write. “In addition, it has
been shown that stent placement compared with balloon angioplasty benefits only
on target vessel revascularization, not mortality.”
The
authors acknowledge, however, that complete information was not obtained in all
patients. Additional limitations include the reliance on self-reported smoking
data and the capturing of information at only 1 year post-PCI and no further,
they note.
Importance
of Natural History:
In a
telephone interview with TCTMD, Ajay J. Kirtane, MD, SM, of Columbia University
Medical Center (New York, NY), said longitudinal studies such as this one are
important because “so much of what we do is based upon 30-day, and 1-year
outcomes. Even the COURAGE trial was only 4.6 years of follow up, so it’s
really important to look at longer data . . . because in some respect they
represent actuarial tables that show us the natural history of these patients.”
Additionally,
he said it reaffirms that patients can reverse some of the smoking-related
damage by quitting.
“So
many times you talk with patients and they think that because they’ve been
smoking so long there is nothing they can do,” Dr. Kirtane said. “But data like
these reiterate the fact that probably for all but the heaviest of smokers,
stopping can drop you back down to a baseline risk equivalent with people who
never smoked. That gives patients hope and it’s important.”
He said
the data are “one more thing in my toolbox to convince patients they should
stop smoking.”
Quoting
Old Data Not Justifiable:
But
Morton J. Kern, MD, of the University of California, Irvine (Irvine, CA), told
TCTMD in a telephone interview that while hard data showing survival advantages
of quitting are helpful, getting patients to make a life change is far more
complicated.
“The
more ammunition you have, the better. But honestly, most people are not swayed
by these kind of data,” he commented. “You can tell them [smoking] is one of
the highest risk factors for stent thrombosis, restenosis, etcetera. After they
have had a heart attack, it’s a little easier to convince them because they’re
scared and sometimes they do need that wake-up call. But if they are not
hurting enough or sick enough, it’s tough.”
Dr.
Kern said he typically speaks with the family about the importance of quitting
as a way of invoking “peer pressure.”
He
dismissed the importance of the study data, however, saying it is “ludicrous”
to try to generalize pre-stent PCI outcomes to a modern population. “Stents
changed the landscape of PCI and in the pre-stent era, all of the outcomes are
totally different from what we see today,” Dr. Kern said. “I don’t see how you
can justify quoting from data that are this old.”
Study
Details:
All PCI
procedures were performed with balloon angioplasty only. The mean age of the
patients was 56.2 years, and most (80%) were men.
POSTED BY: Steven
Almany M.D.
