TURISMO TISOC HERMANOS SOCIEDAD COMERCIAL DE RESPONSABILIDAD

Type 1 and type 2 diabetes mellitus are associated with a greater risk of SIHD, and the effects of other risk factors

such as hypercholesterolemia are magnified (1170). Cardio-

vascular mortality rate is 3-fold higher in men with diabetes mellitus and between 2- and 5-fold higher in women with diabetes than in patients without diabetes mellitus (1171,1172). Sudden cardiac death occurs more frequently in patients with diabetes mellitus. Although direct evidence is lacking, asymptomatic ischemia could be more prevalent in patients with diabetes mellitus, possibly because of

autonomic neuropathy (1173).

The risk of death in a patient with SIHD and diabetes mellitus has been equated to the risk of death in a patient

with SIHD and a previous MI (1171,1174). Aggressive

management of cardiovascular risk factors, including hyper- cholesterolemia, hypertension, smoking, low physical activ- ity, and obesity, is essential, along with appropriate glycemic control.

Among patients with IHD, the presence of concomitant diabetes mellitus increases the risk of adverse events, irre- spective of whether the patient is treated medically or with revascularization. Two studies have suggested that survival

among patients with diabetes mellitus is more favorable after bypass surgery than with medical therapy, although these results are based on subgroup analyses from observa-

tional data (991,1175). Of 2 studies comparing PCI and

medical therapy in patients with diabetes mellitus, one reported longer survival (1175), but the other did not (991). A subgroup analysis of data from the BARI trial sug- gested that patients with diabetes mellitus who underwent CABG with 1 arterial conduit had improved survival

compared with those who underwent PCI (368). Several

retrospective cohort studies have compared outcomes among patients with diabetes mellitus undergoing PCI versus CABG. Three observational studies have reported a survival advantage for CABG over PCI, whereas a fourth found no significant difference, and no studies located reported better outcomes after PCI.

In the BARI 2D study, 2,368 patients with type 2 diabetes mellitus and SIHD were initially selected as can- didates for either PCI or CABG on the basis of clinical and angiographic assessment and then were randomly assigned to undergo either prompt revascularization with intensive medical therapy or intensive medical therapy alone and to undergo either insulin-sensitization or insulin-provision

therapy (408). The study was not designed to compare PCI

with CABG. At 5 years, overall survival was similar between the revascularization and medical-therapy groups (88.3% versus 87.8%), as was the incidence of MACE (77.2%

versus 75.9%) (409). Patients with the most severe CAD

were assigned to the CABG stratum and those with the least severe CAD to the PCI stratum. In the PCI stratum, there was no significant difference in primary endpoints between the revascularization group and the medical- therapy group. In the 763 patients randomized to the CABG stratum, survival was similar but AMI less frequent among those assigned to revascularization plus intensive medical therapy compared with intensive medical therapy

(10.0% versus 17.6%; p⫽0.003), and the composite end-

points of all-cause death or MI (21.1% versus 29.2%;

p⫽0.010) and cardiac death or MI (p⫽0.03) were also less

frequent. Compared with those selected for PCI, patients in the CABG stratum had more 3-vessel disease (20% versus 52%), more total occlusions (32% versus 61%), more prox-

imal LAD stenoses⬎50% (10% versus 19%), and a signif-

icantly higher myocardial jeopardy score (409).

One-year follow-up data from the SYNTAX study dem- onstrated a higher rate of repeat revascularization in patients with diabetes mellitus treated with PCI than in those treated with CABG, driven by a tendency for higher repeat revascularization rates in those with higher SYNTAX scores

undergoing PCI (1006).

A large meta-analysis that included the BARI trial but not BARI 2D failed to identify any significant difference in mortality rate after CABG versus PCI for patients with

diabetes mellitus (1079). In a more recent, collaborative

analysis that pooled patient-level data from 10 randomized trials (again, not including BARI 2D), Hlatky and col-

leagues found that of the 1,233 patients with diabetes mellitus, 23% of those assigned to CABG died, compared

with 29% of those assigned to PCI (1080). By contrast, of

the 6,561 patients without diabetes mellitus, 13% and 14% died, respectively (p⫽0.014 for interaction). The interaction between diabetes mellitus and treatment remained highly significant after adjustment for multiple patient character- istics and after exclusion of patients enrolled in the BARI 2D trial.

Some evidence indicates that the presence of diabetes mellitus adversely affects the outcomes of revascularization. An analysis of the 2009 data on 7,812 patients (1,233 with diabetes mellitus) in 10 RCTs demonstrated a worse long- term survival rate in patients with diabetes mellitus after balloon angioplasty or BMS implantation than after CABG

(1080). Analyses from 3 registries found significantly ele-

vated adjusted ORs for short-term mortality after PCI that ranged from 1.25 to 1.54 in relation to patients without

diabetes mellitus (1144,1146,1165). Data from the STS

registry indicated that patients with diabetes mellitus on oral therapy had an adjusted OR of 1.15 for death within 30 days (95% CI: 1.09 to 1.21), as well as significantly higher odds of stroke, renal failure, or sternal wound infection than those of patients without diabetes mellitus (1167). For patients on insulin, the adjusted OR for death within 30 days was 1.50 (95% CI: 1.42 to 1.58), and the risks for other complications were also correspondingly higher.

In summary, in subjects requiring revascularization for multivessel CAD, current evidence supports diabetes mel- litus as an important factor to consider when deciding on a revascularization strategy, particularly when complex or

extensive CAD is present (Figure 14).

The basis of the currently available data, an intensive approach to reducing cardiovascular risk and symptoms in patients with diabetes mellitus by using GDMT should be the initial approach. For patients whose symptoms are inadequately managed or who experience intolerable adverse effects, revascularization should be considered. CABG might be associated with lower risk of mortality in patients with diabetes mellitus and multivessel disease than PCI, but this remains uncertain. The ongoing FREEDOM (Future Revascularization Evaluation in patients with Diabetes mel- litus: Optimal management of Multivessel disease) trial could help resolve this question (1177).

5.12.4. Obesity

Obese individuals frequently have reduced physical work capacity and exaggerated dyspnea on exertion. Furthermore, weight limits of exercise and imaging equipment preclude testing the very obese (1178,1179). Because of limitations in exercise testing and challenges with imaging through in- creased breast tissue or chest girth, reduced diagnostic accuracy has been reported for obese patients (1180). Because of breast tissue artifact, myocardial perfusion PET is more accurate than myocardial perfusion SPECT for the obese patient (191,193,323), although attenuation-correction algo-

rithms or prone imaging can help improve myocardial perfu-

sion SPECT accuracy (187,188). Intravenous contrast en-

hancement improves image quality in obese patients and results in improved diagnostic certainty for stress echocardiog- raphy (181).