Ischemic heart disease (IHD) is the major cause of mortality among diabetic patients. Diagnosis and man-agement of IHD and heart failure in this patient popula-tion are the same as in subjects without dysglycemia.
I. Differences in the clinical course of IHD in dia-betic patients indicate the need for follow-up assessment of risk factors in this population at least once a year.
II. Indications for diagnostic, functional, and ana-tomic investigations to diagnose IHD and stratify risk in diabetic patients (a cardiology consulta-tion) (Figure 16.1):
1. Presence of typical or atypical cardiovascular symp-toms or signs.
2. Abnormal resting ECG.
3. Concomitant atherosclerotic lesions in carotid or pe-ripheral arteries.
4. Planned intensive physical exercise in subjects > 35 years of age who previously lived a sedentary lifestyle.
5. Diabetes type 1 for > 15 years.
6. Presence of at least two risk factors for IHD in addi-tion to diabetes:
— Dyslipidemia (see Chapter 4);
— Hypertension;
— Smoking;
— Family history of premature atherosclerosis;
— Albuminuria;
— Autonomic neuropathy.
III. Management of stable IHD (chronic coronary syn-drome, according to new terminology proposed
by the European Society of Cardiology [ESC]) in diabetic patients.
1. Initiation of a healthy lifestyle (see Chapter 6).
2. Lipid-lowering therapy to achieve therapeutic targets (see Chapter 4).
3. Reduction or elimination of risk factors for IHD:
— Blood pressure normalization (see Chapter 12);
— Treatment of dyslipidemia (see Chapter 13).
4. Drug therapy for IHD in diabetes
— Antiplatelet therapy:
• Acetylsalicylic acid should be also used in patients
> 40 years of age with diabetes type 1 or 2 and an increased cardiovascular event risk (IHD risk
> 5% during 10 years). Effectiveness of ace-tylsalicylic acid in the primary prevention in diabetic patients at low cardiovascular risk has not been established.
• The recommended acetylsalicylic acid dose is 75–100 mg/day,
• If acetylsalicylic acid is contraindicated, clopi-dogrel 75 mg/day may be beneficial although new antiplatelet agents (i.e., prasugrel and ti-cagrelor) are currently preferred due to their higher effectiveness; if these are unavailable, clopidogrel is recommended,
• In patients after a percutaneous coronary in-tervention (PCI), dual antiplatelet therapy with acetylsalicylic acid 75–100 mg/day and clopidogrel 75 mg/day is recommended. In pa-tients after ACS — acetylsalicylic acid 75–100 mg/day and prasugrel 10 mg/day once daily as a second drug. If this therapy is not avail-able, clopidogrel 75 mg/day is recommended
as the second antiplatelet agent. Duration of dual antiplatelet therapy depends on the presentation of IHD and the type of the im-planted stent. Recommended treatment du-ration is one month after the procedure in stable IHD treated with a bare metal stent (BMS), and 6–12 months after implantation of a drug-eluting stent (DES). In all patients after an acute coronary syndrome, dual antiplatelet therapy for 12 months is recommended;
— Cardioselective beta-blockers or combined alpha1- and beta-adrenergic blockers.
— RAA system inhibitors.
If drug treatment is not successful, coronary revascu-larization should be considered.
Exercise testing and other functional (stress) tests are used to confirm the diagnosis, document ischemia, stratify risk, and guide selection of treatment modali-ties and evaluate their effectiveness. Exercise ECG is still most easily available and thus most commonly per-formed but its sensitivity and specificity for diagnos-ing ischemia is limited, particularly in women. Other functional (stress) tests include stress echocardiography, myocardial perfusion scintigraphy, magnetic resonance imaging (MRI), and positron emission tomography (PET). Among anatomical methods, invasive coronary
tidetector computed tomography (MDCT) may also be useful. Diabetic patients are usually at moderate to high coronary artery disease risk. Functional tests are rec-ommended as first-choice modalities in moderate-risk patients, while coronary angiography is the major first-choice modality in high-risk patients. An advantage of MDCT is its high negative predictive value and thus this modality is mostly useful to exclude significant coronary artery disease. However, it s not recommended in high-risk patients, as it results in unnecessary contrast agent and radiation exposure.
REFERENCES
1. Antithrombotic Trialists’ (ATT) Collaboration, Baigent C, Black- well L et al. Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials. Lancet 2009; 373: 1849–1860.
2. Cholesterol Treatment Trialists’ (CTT) Collaborators, Kearney PM, Blackwell L, Collins R et al. Efficacy of cholesterol-lowering therapy in 18,686 people with diabetes in 14 randomised trials of statins:
a meta-analysis. Lancet 2008; 371: 117–125.
3. Gaede P, Lund-Andersen H, Parving HH, Pedersen O. Effect of a multifactorial intervention on mortality in type 2 diabetes.
N Engl J Med 2008; 358: 580–591.
4. Shepherd J, Barter P, Carmena R et al. Effect of lowering LDL cholesterol substantially below currently recommended levels in patients with coronary heart disease and diabetes: the Treating to New Targets (TNT) study. Diabetes Care 2006; 29: 1220–1226.
5. 2018 ESC/EACTS Guidelines on myocardial Revascularization Figure 16.1. An algorithm for the diagnosis of and risk stratification in ischemic heart disease (IHD) in diabetic patients.
ECG — electrocardiogram; MET — metabolic equivalent
16.1. Management of acute coronary syndromes in diabetic patients
— antihyperglycemic therapy
In acute coronary syndromes, normalization of blood glucose levels using intravenous insulin infusion is rec-ommended in order to maintain relative hyperglycemia, which should be defined as blood glucose level above 140 mg/dL (7.8 mmol/L) in subjects with established diabetes and above 180 mg/dL (10.0 mmol/L) in sub-jects without a previous diagnosis of diabetes. Intrave-nous insulin administration is the only approach that allows rapid normalization of blood glucose levels and improvement of outcomes following an acute coronary syndrome. If possible, a diabetologist should be involved in the management of IHD in patients with dysglycemia.
I. The first day of an acute coronary syndrome 1. Stop oral antidiabetic agents.
2. Measure blood glucose on admission in all patients with an acute coronary syndrome.
3. If blood glucose is above 140 mg/dL (7.8 mmol/L) in subjects with established diabetes or above 180 mg/
/dL (10.0 mmol/L) in subjects without a previous diag-nosis of diabetes, initiate intravenous insulin infusion at the rate shown in Table 16.1.1. Recommended frequencies of blood glucose measurements during daytime: every 1 hour, followed by every 2 hours when blood glucose levels become stabilized. Blood glucose level should be kept at 100–180 mg/dL (5.6–
–10 mmol/L) by adjusting appropriately the rate of insulin infusion.
4. Serum potassium level should be monitored during insulin infusion.
Most important recommendations
• On admission, blood glucose level should be measured in patients with an acute coronary syndrome, along with HbA1c level in diabetic patients if no current measurement is available. [A]
• Intravenous insulin infusion with target blood glucose levels of 100–180 mg/dL is recommended during the first day of an acute coronary syndrome. [C]
If blood glucose increases above 180 mg/dL (10 mmol/L), temporarily stop intravenous glucose infu-sion, restarting it when blood glucose falls to 180 mg/dL (10 mmol/L), and at the same time increase the rate of intravenous insulin infusion.
5. If meals are consumed by the patient, add intrave-nous boluses of a short-acting insulin.
6. If diabetic ketoacidosis is present, treat accordingly (Chapter 15).
II. From the second day of an acute coronary syn-drome until discharge
1. Target blood glucose values during glucose-lower-ing therapy are 100–180 mg/dL (5.6–10.0 mmol/L) throughout 24 hours. Thus, treatment must be in-dividualized, preferably in cooperation with a diabe-tologist.
2. In patients without evidence of acidosis, with dysgly-cemia diagnosed on the first day of an acute coro-nary syndrome or with previous successful metformin treatment, appropriate diet may allow adequate met-abolic control of diabetes in this period (Chapter 6).
In the remaining cases, initiate insulin therapy with multiple injections as described earlier (Chapter 11).
3. In overweight or obese patients with diabetes type 2, metformin may be started before discharge, even as early as on the third day after the coronary interven-tion, if not contraindicated. A reduction in insulin dose may be possible after 2–3 days of metformin therapy.
Table 16.1.1. Approximate insulin infusion rate in relation to blood glucose level
Blood glucose 10% dextrose [ml/hour] Insulin [unit/hour]
< 100 mg/dL (< 5.5 mmol/L) 50 Stop infusion for 15–30 minutes
100–140 mg/dL (5.5–7.8 mmol/L) 50 0.5–1.0
140–180 mg/dL (6.7–10.0 mmol/L) 50 1.0–2.0
180–250 mg/dL (10.0–13.9 mmol/L) Stop infusion until blood glucose < 180 mg/dL
(10.0 mmol/L) then 50 2.0–4.0
250–300 mg/dL (13.9–17.4 mmol/L) Stop infusion until blood glucose < 180 mg/dL
(10.0 mmol/L) then 50 4.0–6.0
betes, oral glucose tolerance test (see Chapter 1, III, Table 16.1.1.) should be performed before discharge.
A consultation with a diabetologist should be conducted if glucose intolerence or diabetes is diagnosed.
Note 2: Metformin should be withdrawn at least 48 hours before elective diagnostic or therapeutic cardiac catheterization/coronary angiography. The drug may be resumed 24 hours after coronary angiography.
REFERENCES
1. NICE-SUGAR Study Investigators, Finfer S, Chittock DR, et al. In-tensive versus conventional glucose control in critically ill patients.
N Engl J Med 2009; 360: 1283–1297.
2. Ritsinger V, Malmberg K, Mårtensson A, et al. Intensified insulin-based glycaemic control after myocardial infarction: mortality during 20 year follow-up of the randomised Diabetes Mellitus Insulin Glucose Infusion in Acute Myocardial Infarction (DIGAMI 1) trial. Lancet Diabetes Endocrinol 2014; 2: 627–633.
3. Umpierrez GE, Reyes D, Smiley D, et al. Hospital discharge algorithm based on admission HbA1c for the management of patients with type 2 diabetes. Diabetes Care 2014; 37:
2934–2939.
III. Following discharge
Metformin should be started in all patients with dia-betes type 2 after an acute coronary syndrome, unless contraindicated or not tolerated.
In patients with diabetes type 2 in whom good meta-bolic control (see II.1 in this chapter) was achieved at the time of discharge and daily insulin requirement does not exceed 30 units, it is possible to return to previous glu-cose-lowering treatment that was used before the acute coronary syndrome. In overweight or obese patients with diabetes diagnosed during the hospital stay and good metabolic control (see II.1) achieved at the time of dis-charge, with daily insulin requirement not exceeding 30 units, oral metformin therapy may be used, combined with other agents if needed. If good metabolic control cannot be achieved or daily insulin requirement exceeds 30 units, insulin therapy should be continued. Following an acute coronary syndrome, each patient with dysglyce-mia should be urgently referred to a diabetologist.
Note 1: In all patients with an acute coronary syn-drome, except for those with previously established
dia-Most important recommendations
• Hyperglycemia on admission in the acute phase of stroke is associated with higher mortality, more severe course of stroke, and more severe neurological deficit in both diabetic and non-diabetic subjects. [A]
• Available studies do not provide evidence that correction of hyperglycemia in the acute phase of stroke improves outcomes. [C]
• Current recommendations regarding correction of hyperglycemia in stroke are based only on expert opinion. [E]