Progress Report - January 2008

Since the update in October 2007, the focus has been on gathering more confirmed cases of myocarditis, so that we can publish our results thus far as a case series.  This will provide evidence-based guidance for the monitoring and diagnosis of myocarditis.

Confirmed cases

The total number of confirmed cases is now 31:

• 23 men and 8 women
• Aged 22-74 (mean 37) years
• Clozapine duration 14-21 (mean 17) days for 29 cases with 2 outliers at 26 and 33 days

Recovery after myocarditis

Data on cardiac follow-up after the acute event was available for 14 cases, and this information shows:

• Recovery may be rapid, within 10 days as determined by echocardiogram
• Those recovering more slowing may nevertheless recover full cardiac function
• Two patients had no residual effects after long-term follow-up of > 5 years

We have now documented 3 cases of possible missed myocarditis, where clozapine was continued after the adverse reaction.  The respective outcomes for the 3 patients were:

• death from heart failure some months after clozapine cessation
• persisting cardiac impairment at 9 months
• normal left ventricular function 10 weeks after stopping clozapine

Rechallenge

Rechallenge has been documented in 7 cases:

• One had recurrence of myocarditis – after a single 400mg dose
• 3 became ill within the first 7 days and clozapine was stopped without documentation of myocarditis
• 3 continued clozapine without recurrence of myocarditis

Caution:  The long term impact of re-instating clozapine after myocarditis is unknown.