Ventricular tachycardia and sudden death after primary PCI-reperfusion therapy: impact on primary prevention of sudden cardiac death.

BACKGROUND

Current approaches to coronary artery disease (CAD) and acute myocardial infarction (MI) may not be well represented in most primary prevention trials of sudden cardiac death (SCD).

METHODS

The contemporary and ongoing registry of the Rostock infarction network (Drip & Ship) represents a well-defined cohort of patients subjected to percutaneous coronary intervention (PCI) for ST-elevation infarction (STEMI) and served as the database for both candidates for an ICD for primary prevention of SCD and for sudden death (SCD) or ventricular tachycardia (VT) during follow-up.

RESULTS

A total of 855 consecutive patients were treated with PCI for STEMI or NSTEMI in the region of Rostock (Germany) between 2001 and 2004. While all cause mortality was still 17.2%, the SCD rate was low at 1.3% during 728 ± 366 days of follow-up. Within that time 85 patients (9.9%) developed an indication for ICD therapy due to an impaired LV function (LVEF ≤ 35%) and heart failure. Univariate predictors of an ICD indication were delayed reperfusion (p = 0.001), a high creatine kinase (CK) max (p = 0.009), a persistent wide QRS complex (p = 0.001), previous cerebrovascular events (p = 0.033), and chronic renal failure (p = 0. 001). However, only 16.5% of these patients qualifying for an ICD actually received an ICD; nevertheless, the actual SCD rate was only 3.5%, while 5.4% (46 patients) suffered VTs or ventricular fibrillation (VF). The SCD/VT rate in the entire infarct population was associated with time to reperfusion (0.032), left bundle-branch block (0.002), a longer history of CAD (0.032), and VT during follow-up.

CONCLUSION

While mortality in patients with STEMI is still alarming even with PCI, the risk of SCD may be considerably decreased even in patients with an LVEF below 35%. With the current approach to primary prevention of sudden cardiac death, approximately 10% of postinfarction patients qualify for ICD therapy; however this may only reach a quarter of patients prone to SCD.