Iscoli ischemia

Painless ischemia is the detection of signs of myocardial ischemia, not accompanied by angina attacks or their equivalent, during instrumental research methods (Holter monitoring of ECG-HMECG, stress tests). It is believed that the absence of pain syndrome, despite the development of myocardial ischemia, is associated with an increased threshold of pain sensitivity, impaired endothelial function, defects in vegetative innervation of the heart.

[1], [2], [3], [4]

Epidemiology of painless ischemia

The prevalence of painless ischemia is difficult to assess, and on average it ranges from 2.5% in the general population to 43% among patients with different forms of ischemic heart disease. According to most researchers, painless ischemia is independent (especially in patients with acute coronary syndrome) an unfavorable risk factor for long-term prognosis, although the evidence base for this is still insufficient.

[5], [6], [7], [8], [9], [10], [11]

Classification of painless ischemia

The most common classification is Cohn, according to which three types of painless ischemia are distinguished: type 1 in patients without any symptoms of angina pectoris; type 2 in patients with painless myocardial ischemia after a myocardial infarction; and type 3, when one patient combines angina attacks and painless episodes of myocardial ischemia.

[12], [13], [14], [15]

Treatment of painless ischemia

The issue of optimal management of patients with painless myocardial ischemia both with regard to the use of medications and invasive treatment has not yet been resolved. Completed 2 studies comparing medical and invasive treatment in patients with painless ischemia of the 2nd and 3rd types. The ACIP study included patients without angina pectoris or with angina pectoris who were well controlled by drug therapy, hemodynamically significant stenoses of coronary arteries were detected with CAG, a load test for ischemia was positive and at least one episode of painless myocardial ischemia was detected with 48 hours of HMEC (t ie, patients with type 3 painless ischaemia).

When eligibility criteria were met, patients were randomized into three groups: drug therapy focused on arresting angina attacks (184 patients), drug therapy titrated before the disappearance of not only angina attacks, but also painless episodes of myocardial ischemia in HMECG (182 patients) and group myocardial revascularization (192 patients), in which, depending on the anatomical features revealed in CAG, CABG or PCI was performed. After 2 years of follow-up, mortality in the invasive treatment group was significantly lower than in the group of drug therapy (6.6% in the treatment group for angina, 4.4% in the ischemia group, 1.1% in the myocardial revascularization group) . There was also a significant decrease in the incidence of the combined endpoint, death / myocardial infarction (12.1, 8.8 and 4.7%, respectively). During the study, 29% of patients who were initially randomized to medication, required an invasive intervention. Patients from the invasive treatment group also needed a re-hospitalization due to the exacerbation of IHD. Particularly favorable effect on the prognosis of invasive treatment was in patients with stenoses in the proximal part of the PNA.

In 2008, data from the SWISSI study comparing the influence of percutaneous coronary plasty and drug therapy in patients with recent myocardial infarction, who were diagnosed with painless myocardial ischemia (no type 2 ischemia), were published in 2008. Patients with single- and double-vessel coronary artery disease were included in the study. When eligibility criteria were met, patients were randomized to the TBA group (96 patients) and to the intensive medication group (95 patients), aimed at eliminating episodes of myocardial ischemia. All patients received acetylsalicylic acid (ASA) and statins. After 10.2 years of follow-up, a significant reduction in CAS by 81%, non-fatal myocardial infarction by 69%, need for myocardial revascularization due to the appearance of a clinic for angina by 52% was noted in the invasive treatment group. There was also a trend towards a significant reduction in overall mortality by 58% (p = 0.08). Even after 10 years of observation, despite the more frequent combination of antianginal therapy in the drug treatment group, TBCA remained more effective in relieving patients of ischaemia (according to the data of the stress test at the time of completion of the observation), and increased exercise tolerance more.

In the invasive treatment group, preservation of the initial LVEF was noted, while in the group of drug therapy LVEF decreased significantly from 59.7 to 48.8% during the observation period. The survival curves began to diverge after 2 years of follow-up, with the discrepancy continuing throughout the follow-up period. It should be emphasized that, in view of the timing (set from 1991 to 1997), stents were not used in PCI in this study, and drugs such as clopidogrel, angiotensin-converting enzyme (ACE inhibitors), high doses of stagins and other drugs are standard modern therapy of patients after a heart attack, therefore, the applicability of these results to modern conditions is difficult to determine. Unlike observations with stable angina pectoris (including COURAGE) in the case of painless myocardial ischemia, both studies comparing PCI and drug therapy showed the advantage of an invasive approach in terms of not only reducing the severity of ischemia but also affecting the hard endpoints death, myocardial infarction, the need for repeated revascularization).

According to the latest recommendations of ACCF / SCAI / STS / AATS / AHA / ASNC (2009), in the case of painless ischemia, when choosing an invasive and conservative tactic, it is necessary to focus on data from noninvasive research methods, as well as the anatomical characteristics of coronary lesions. The presence of a three-vessel lesion, the destruction of the proximal segment of the PNA, the presence of high-risk criteria for CCC in non-invasive methods of investigation - all this is the basis for the choice in favor of invasive treatment. Conversely, in single-vessel lesions that do not affect PNA, combined with a low risk of SSS, according to the data of stress tests, drug therapy is performed.

Basic provisions:

• Painless ischemia is an independent risk factor that worsens the long-term prognosis of patients.
• There are three types of painless ischemia, depending on the presence of a history of myocardial infarction and angina attacks
• Treatment of painless ischemia can be performed conservatively (the goal of treatment is to eliminate ischemia) or invasively, in particular with the help of PCI. The question of PCI should be addressed in each patient individually, taking into account the data of non-invasive research methods, as well as anatomical characteristics of the lesion of the coronary bed.
• The presence of a three-vessel lesion, damage to the proximal segment of the PNA, the presence of high-risk criteria for CCC in non-invasive methods of investigation serve as the basis for the choice in favor of invasive treatment.
• Carrying out PCI in asymptomatic patients with one- or two-vessel lesions that do not affect the proximal segment of the PNA, with a low risk of CVS from the data of stress tests is not recommended.