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Bypassing Obesity: Should there be a STAMPEDE
to More Bariatric Surgery
O
besity and diabetes appear to be the major
drivers of cardiovascular disease and, in
particular, coronary artery disease. Current medical based therapies for these conditions
are not effective for everybody.
While bariatric surgery is still discussed as a
means of achieving weight loss among the chronically – and usually morbidly – obese, the conversation has shifted to thinking of it more as metabolic
surgery or “comorbid condition resolution.” Plus,
there is increasing emphasis on considering this
approach a little earlier.
This effort has been reinforced by the STAMPEDE trial (Surgical Therapy And Medications
Potentially Eradicate Diabetes Efficiently).1 This randomized, controlled, single-center study compared
intensive medical therapy with optimal therapy plus
surgical treatment as a means of improving glycemic control in obese patients with type 2 diabetes.
Investigators screened 218 patients at the
Cleveland Clinic and assigned 150 eligible patients
to undergo intensive medical therapy alone or
intensive medical therapy plus either Roux-en-Y
gastric bypass or sleeve gastrectomy. Bariatric
procedures were performed laparoscopically by
a single surgeon. Gastric bypass consisted of the
creation of a 15-to-20 mL gastric pouch, a 150
cm Roux limb, and a 50 cm biliopancreatic limb.
Sleeve gastrectomy involved a gastric-volume
reduction of 75% to 80% by resecting the stomach
alongside a 30-French endoscope beginning 3 cm
from the pylorus and ending at the angle of His.
TABLE
(BMI > 30 kg/m2) and relatively advanced, poorly
controlled diabetes, including many patients with
diabetes-related coexisting illnesses or evidence
of end-organ damage. Patients had an average
disease duration of more than 8 years and a mean
baseline glycated hemoglobin (HbA1c) level of
8.9% to 9.5%. At baseline, study participants were
receiving, on average, nearly 3 antidiabetic agents,
including a relatively high use of insulin (44% of
patients) or other injectable therapies (14%).
STAMPEDE RUNS TO 5 YEARS
The primary endpoint was the proportion of
patients with an HbA1c level of 6% or less (with
or without diabetes medications) 12 months after
randomization. (Average baseline level was 9.2 ±
1.5%.) Patients undergoing surgery were significantly more likely to achieve a glycated hemoglobin
level of ≤ 6.0% 1 year after randomization than
patients receiving intensive medical therapy alone.
Philip Raymond Schauer, MD, and colleagues
subsequently presented 3-year follow-up: compared
to intensive medical therapy, bariatric surgery was
associated with superior and sustained glycemic
control and weight reduction.2
The primary endpoint, HbA1c ≤ 6%, was
achieved in 5% of intensive medical therapy
patients, 37% of gastric bypass patients, and 24%
of sleeve gastrectomy patients. Nearly all gastric
bypass patients who achieved the primary endpoint target did so without requiring any diabetic
medications (oral or injectable) while 20% of sleeve
Medical Therapy
(n = 38)
Bypass
(n = 49)
Sleeve
(n = 47)
p Value*
p Value†
HbA1c ≤6%
5%
29%
23%
0.005
0.02
HbA1c ≤6% (without DM meds)
0%
22%
15%
0.002
0.02
HbA1c ≤7%
21%
51%
49%
0.004
0.008
Relapse of glycemic control
80%
40%
50%
0.16
0.34
*Gastric bypass versus medical therapy.
†Sleeve versus medical therapy
DM = diabetes mellitus; HbA1c = glycated hemoglobin.
In medical terms, morbid obesity is usually
described as a body mass index (BMI) of 40, or 35
to 40 with significant medical issues caused by or
exacerbated by weight. A BMI of 40 amounts to
approximately 100 pounds above ideal weight. The
study population had moderate to severe obesity
ACC.org/CSWN
• More than 88% of gastric bypass and sleeve
gastrectomy patients maintained healthy blood
glucose levels without the use of insulin.
• 29% of gastric bypass patients and 23% of
sleeve gastrectomy patients achieved and
maintained normal blood glucose levels, compared to just 5% of those on medication alone.
• Weight loss was significantly greater with gastric bypass and sleeve gastrectomy than with
medications and was the primary driver for
glucose control.
Final 5-Year STAMPEDE Results
Parameter
gastrectomy group versus a reduction of 4.2 ±
8.3% in the medical therapy
group (p < 0.001 for both
comparisons). Quality-of-life
(QOL) measures were not
evaluated at 1-year follow-up,
but were added to the 3-year
results. Investigators reported
significantly better QOL in the
To listen to an
interview with
2 surgical groups than in the
Philip Raymond
medical therapy group, with
Schauer, MD, on
the greatest improvement seen
the 5-year results
of the STAMPEDE
in the gastric bypass patients.
trial, scan the code.
There were no major late surgiThe interview was
conducted by Huon
cal complications.
H. Gray, MD.
Now, final 5-year data
have been reported (TABLE)
suggesting superior results
with surgery and the curves
continue to widen over time in
support of surgical intervention. In brief:
gastrectomy patients achieved target without medications.
Patients in the surgical groups had greater mean
percentage reductions in weight from baseline, with
reductions of 24.5 ± 9.1% in the gastric bypass
group and 21.1 ± 8.9% in the laparoscopic sleeve
• The effects of both surgical procedures to normalize glucose levels did, however, diminish over time
with some late complications noted with surgery.
There were no late major complications of surgery except for one reoperation (a successful laparoscopic conversion of sleeve gastrectomy to gastric
bypass for recurrent gastric fistula) that occurred 4
years after randomization.
Significant and durable improvements in bodily
pain and general health were demonstrated using a
validated QOL instrument in both surgical groups
relative to the medical group. Several biomarkers
associated with heightened cardiovascular risk
were reduced in the surgical arms, but there were
no beneficial effects on retinopathy or nephropathy
seen at 5 years.
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